Galileo WebChat - October 30, 1996
9:00 AM - 12:00 PM PST

Nancy Vandermey,SEQ-Systems: . . . . Wed, Oct 30, 9:10AM PDT (-0700 GMT)
Signing in...

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:10AM PDT (-0700 GMT)
test

Ashwin Vasavada, SSI Affiliate: . . . . Wed, Oct 30, 9:10AM PDT (-0700 GMT)
Hi, I'm here...

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 9:11AM PDT (-0700 GMT)
Hello, I'm on also

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 9:11AM PDT (-0700 GMT)
Online

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:11AM PDT (-0700 GMT)
prepare to make the jump to lightspeed...

Marcia Segura, NIMS Science Coordinator: . . . . Wed, Oct 30, 9:12AM PDT (-0700 GMT)
Hi Folks... Signing in.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 9:12AM PDT (-0700 GMT)
Good Morning Everybody :)

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 9:12AM PDT (-0700 GMT)
howdy...

Steven Tyler, Systems Engineer: . . . . Wed, Oct 30, 9:13AM PDT (-0700 GMT)
I'm here too.

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 9:13AM PDT (-0700 GMT)
Anyone from *outside* Galileo on yet?

J Erickson, Science & Sequence Office: . . . . Wed, Oct 30, 9:13AM PDT (-0700 GMT)
I'm here also.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:13AM PDT (-0700 GMT)
Yeah! We'll outnumber'em! AHAHAHAHAH!

anonymous: . . . . Wed, Oct 30, 9:14AM PDT (-0700 GMT)
Hi, all, we got it up and running, just a little late. Thanks for participating! Let's get the public here now, right! BTW, we need pizza contest entries - you guys gonna come and make a pizza next monday?

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 9:14AM PDT (-0700 GMT)
Well - both OPNAVs from yesterday afternoon were successful.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:15AM PDT (-0700 GMT)
Laura, I know a pizza place that might be interested...

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 9:16AM PDT (-0700 GMT)
Here I am......any questions, say from Systems ;-)

Tolis: . . . . Wed, Oct 30, 9:16AM PDT (-0700 GMT)
Hello There. I'm a lowly astronomy research student currently living in England and I would just like to ask ONE (1) question. I have noticed a discrepancy between the contents of the Timetable of Events page (in the SEPO home page) for the C3 orbit and the C3 timeline contained in the Countdown to Callisto page. Namely, the rings and small satellites observations present in the former are absent in the latter. Which one is correct? Thanks.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 9:17AM PDT (-0700 GMT)
Well Lou, as long as I have you here: what are the chances go designing the maneuver tonite?

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 9:17AM PDT (-0700 GMT)
Where oh where is the flood of questions?

Nancy Vandermey,SEQ-Systems: . . . . Wed, Oct 30, 9:18AM PDT (-0700 GMT)
Very funny Shadan.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:18AM PDT (-0700 GMT)
Hi everyone, thanks for your patience. Our usual web master is out of town, and we are having a rough start. I just realized why we have no public folks on board, and we should have that fixed in just a couple of minutes... arghhhhhhh

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 9:18AM PDT (-0700 GMT)
We are going to design the maneuver tonight - starting at 8:00 PM. But the maneuver may not be performed, depending the current error and uncertainties.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:20AM PDT (-0700 GMT)
Hi Tolis, I'm checking this out with our local mission planner, and I'll get back to you shortly.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 9:20AM PDT (-0700 GMT)
Good question about the events. If they're all that hard we're in trouble. I note that they are not in my book but its a couple of months old and things change faster than that lately.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 9:20AM PDT (-0700 GMT)
Hello Tolis, I someone can get you an answer pretty soon.

Nancy Vandermey,SEQ-Systems: . . . . Wed, Oct 30, 9:21AM PDT (-0700 GMT)
Tolis: the Countdown page is not as detailed as some other timelines; there are still 2 small satellite images planned in C3 (Thebe and Amalthea)

Rush: . . . . Wed, Oct 30, 9:21AM PDT (-0700 GMT)
I wanted to say that I enjoy all the images and other data that appear almost everyday. My question is have scientists found out conclusively whether Ganymede has a magnetic field.

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 9:21AM PDT (-0700 GMT)
For Tolis: I don't have either of the documents you're referring to in front of me, but my guess would be that the former (containing info about the rings and small satellites observations) is correct. Not every single observation, or even every group of observations can always be called out on these various summaries.

anonymous MM: . . . . Wed, Oct 30, 9:21AM PDT (-0700 GMT)
Hi, I'm new at this and am not sure about what I am doing. This for me will be a test and/ or trial! Thanks for any tips you can give.

Chris Hughes (Westborough, MA): . . . . Wed, Oct 30, 9:21AM PDT (-0700 GMT)
Is there any possibility that the orbiter could be put into orbit around one of the satellites as part of the extended mission? I would imagine it would take too much propellant unless there's some way to use gravity assist.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 9:22AM PDT (-0700 GMT)
Hi Tolis, The ring observations begin on November 8th at 20:15 PST approx.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 9:22AM PDT (-0700 GMT)
Chris: You are correct. It would require much more propellant than we have available.

JeffS: . . . . Wed, Oct 30, 9:23AM PDT (-0700 GMT)
Good morning Galileo team. Thanks for doing another web chat. In examining the Io picture P47972 released 10/23, the volcano Prometheus has what looks like a plume twisting as it rises from the surface.

Jim Erickson, Science & Sequence Office: . . . . Wed, Oct 30, 9:23AM PDT (-0700 GMT)
Tolis- We still have in the plan for there to be both ring observations and small satellite observations (Thebe and Amalthea). Sorry, but I don't recognize either of those web pages.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 9:24AM PDT (-0700 GMT)
Lou, I guess i was asking what are *my* chances of designing the maneuver at 1am (but i guess you won't know that until you design it from your end)

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 9:24AM PDT (-0700 GMT)
Hi, folks. Propulsion is ready to chat!

Tal Brady..Flight Software: . . . . Wed, Oct 30, 9:24AM PDT (-0700 GMT)
Hi anonymous, looks like your working Ok. You might put a name in your handle box so we can answer directly.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 9:24AM PDT (-0700 GMT)
Shadan: We'll probably be done by 1:00 AM.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 9:24AM PDT (-0700 GMT)
Hi Chris, as Lou said, Galileo can't do it, but there are plans for later missions such as a Europa Orbiter which would. It takes a lot of propellant and some fancy navigation as well.

Jim Erickson, Science & Sequence Office: . . . . Wed, Oct 30, 9:25AM PDT (-0700 GMT)
Offline for an hour.

Nancy Vandermey,SEQ-Systems: . . . . Wed, Oct 30, 9:25AM PDT (-0700 GMT)
Chris: The current extended mission plan is GEM (Galileo Europa Mission), with Europa targeted over 10 more times, then Io once or twice before radiation s gets us

Tolis: . . . . Wed, Oct 30, 9:26AM PDT (-0700 GMT)
Thank you very much indeed. I wish you lots of exciting results (and publications).

Jan Ludwinski, Mission Planning Office: . . . . Wed, Oct 30, 9:26AM PDT (-0700 GMT)
I'm online now.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 9:26AM PDT (-0700 GMT)
Chris: I just wanted to point out that GEM has not been funded yet, and it's more like 8 additional Europa encounters.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 9:27AM PDT (-0700 GMT)
Chris, However any extended mission plans I have heard do include a fair number of Europa passes and of course the poor computer is so slow that it needs a long non-encounter period to return the data anyway.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 9:27AM PDT (-0700 GMT)
Hello there, SEQ integrator is ready

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 9:27AM PDT (-0700 GMT)
For JeffS: I think that the feature you're referring to is a dark flow of material extending to the right of the summit of Prometheus. That's not part of the plume, it's most likely a flow of material that was erupted from the volcano and flowed on the surface. The plumes are pretty transparent when we look straight down through them to the surface.

Bartman: . . . . Wed, Oct 30, 9:28AM PDT (-0700 GMT)
I have seen some of the stereographic pictures/photos from Ganymede, but did they help you learn anything, or just supply you with the means for some pretty 3D pictures?

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 9:28AM PDT (-0700 GMT)
Sorry, gotta run. back in 60 minutes

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:29AM PDT (-0700 GMT)
Hi Tolis, thanks for checking up on us! Are you doing research on rings or small satellites? The SEPO page focuses on the imaging experiment, whereas the main Countdown Page covers all the instruments on Galileo, so we must narrow down the main list. We will add this in now, however.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 9:29AM PDT (-0700 GMT)
Chris: and after the Europa encounters, we'll do a handful of Callisto encounter to lower our perijove so we can have a encounter with Io

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:29AM PDT (-0700 GMT)
Hi, I'm Steve Collins. I work on the Galileo Orbiter Engineering team as part of the AACS unit. AACS Stands for Attitude and Articulation Control System. We're responsible for all the sensors and computers on Galileo that figure out and control where the spacecraft and camera platform is pointed. I have 2 bachelors degrees. One in Physics and the other in Theatre Arts. Hobby wise, I do rock climbing, play with computers, ride mountain bikes and do ballet and modern dancing. Here at JPL I'm involved with outreach, the JPL Urban Seach and Rescue Team and the first New Millenium Project, DS-1

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 9:30AM PDT (-0700 GMT)
Good Morning Galileo! I have no students here yet but I expect them to be passing through starting at 10AM. My question is: what's the deal on Ganymede? Magnetosphere or no magnetosphere?

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 9:31AM PDT (-0700 GMT)
Bartman, that kind of question strikes fear in the hearts of scientists. As you can see from our images, we have better resolution than Voyager as well as stereo coverage. These allow geologists (most of whom are at a big meeting today) to develop theories of how the surface formed, derive relative ages, study faults, vulcanism, etc. Some Voyager-era theories of Ganymede have been turned upside-down by Galileo images.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 9:31AM PDT (-0700 GMT)
Hi JeffS. Thanks for participating. In the imaging data, there was a plume discovered. However I don't recall if it was Prometheus. There has been notable surface changes since Voyager first observed Io. In fact, there appears to be differences from Galileo's first to second orbit. In the NIMS data, we can see areas that are "hotter" in the second orbit.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 9:31AM PDT (-0700 GMT)
Bartman: Among other things, the 3D images provide information like how high are the peaks and how deep are the valleys

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 9:32AM PDT (-0700 GMT)
Time for a propulsion fun fact! Did you know the Galileo propellant combination (monomethylhydrazine, MMH, for the fuel and nitrogen tetroxide, NTO, for the oxidizer) is the same combination used for small adjustments to the space shuttle while in orbit? Also, this propellant combination was utilized for the Titan II missles, dozens of which were secretly buried in missle silos outside of my hometown of Wichita, Kansas, ready to partake in World War III (back in the days of the cold war, of course).

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:32AM PDT (-0700 GMT)
Bartman: The stereographic pictures allow us to determine the heights or depths of the surface features more precisely than with just one picture.

Jan Ludwinski, Mission Planning Office: . . . . Wed, Oct 30, 9:33AM PDT (-0700 GMT)
GEM will have 8 Europa encounters followed by 4 Callisto encounters, followed by an Io encounter in October 1999. It's important to note that the $ for GEM has not yet been appropriated, and there are many competing uses for that $.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 9:33AM PDT (-0700 GMT)
Hi, Paul -- How are ya doin. I think the Magnetospere is still contraversial at the moment. The MAG people presenting here seem to be cautiously voting for one.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 9:34AM PDT (-0700 GMT)
I'll also introduce myself. I'm Leo Cheng. I work on the Sequence Team, the team responsible for producing the "sequence" of commands that execute on the spacecraft. My job is the Sequence Integration Engineer or SIE. SIE's takes the lead role in "integrating" or putting together all of the commands, comming from variious subsystems on Galileo. I have a B.S and an M.S. in physics. My hobbies include: swing dancing, telescope building, and flying.

Bartman: . . . . Wed, Oct 30, 9:34AM PDT (-0700 GMT)
Shadan: Do you have no other instruments (such as high resolution radar or laser... I know if I had read your web pages carefully I would know the exact instruments, but) that can tell give you a 3D topographical map? If not, is this something that some planetary probes do have?

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:34AM PDT (-0700 GMT)
Hi Paul: Ganymede does have its own magnetosphere. I saw the talks at the DPS (Division of Planetary Sciences) talk in Tucson last week. Our magnetometer person is out of his office right at the moment.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:34AM PDT (-0700 GMT)
Paul, Ganymede clearly has some kind of magnetosphere. The source of Ganymede's magnetic field is still the matter of much debate. The leading theory is some kind of molten Iron core, but circulation of liquid water has also been proposed. I'm sure the science types can say more...

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:35AM PDT (-0700 GMT)
GALILEO TEAM: Those of you who haven't already, please introduce yourself to the folks. THANKS!

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 9:36AM PDT (-0700 GMT)
Yeah, what Steve said.....but I ride road bikes.

Gerhard: . . . . Wed, Oct 30, 9:36AM PDT (-0700 GMT)
Hi! I´m a biochemistry student from Vienna, Austria. I would like to ask if there were any surprises or unexpected features found on the highest resolution photos of the Ganymed surface. Can it be said yet if this area is made entirely of ice, or mixed ice and rock ?

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 9:36AM PDT (-0700 GMT)
I'll second the fact that Ganymede definitely has its own magnetic field. The question is whether it is active (are there fluids like water or a molten core powering the field, called a dynamo :) or is it a remnant field from Ganymede's formation. Both are possible at this point.

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 9:39AM PDT (-0700 GMT)
My intro- I'm one of the people who's responsible for making sure the tape recorder ("DMS") & main Command & Data Subsystem (CDS) onboard computers maintain the health & safety of Galileo ("work correctly").

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 9:39AM PDT (-0700 GMT)
I guess I should be more specific. I know G1 showed a clear signature from Ganymede in the Jupiter magnetosphere but the controversy was over whether it was an intrinsic Ganymede field that was the cause. The G2 over the pole trajectory was advertised as 'answering the question'. Did it?

Nancy Vandermey,SEQ-Systems: . . . . Wed, Oct 30, 9:39AM PDT (-0700 GMT)
I work on the sequence team as a systems engineer, helping to ensure the commands we send to the spacecraft won't cause it to crash. I do volunteer work with big cats on the weekends, and design a Web site for the Cathouse ;-)

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 9:39AM PDT (-0700 GMT)
Bartman, I have a small answer for your question (forgive me, Shadan, for jumping in). One of the best tools for measuring surface topography is a laser altimeter, which works by bouncing a laser beam off of a surface, timing the return of its reflection, and working out details of the distance to the body that way. This can give very detailed data about the vertical relief of a planetary surface. One (soon-to-be!) in-flight example of this is on Mars Global Surveyor, which is due to launch one week from today! I think you can read more about that mission and laser altimetry at this button

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 9:41AM PDT (-0700 GMT)
I'm the Deputy Navigation Team Chief. I've been working on galileo for 19 years (my entire career at JPL). I have a BS, MS, and PhD in Aeronautical Engineering. Besides working on Galileo, I enjoy bike riding, reading, traveling, photography, and gardening.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 9:41AM PDT (-0700 GMT)
Intro: Galileo trajectory optimizer, supervisor of the Outer Planets Mission Analysis Group. Numbers freak! I do statistics on things like the stock market and NFL football scores. I play racquetball moderately well and run on the treadmill to keep in shape. My children are married, son a doctor, daughter a hospital administrator. I am a science fiction fan and love working in the space program (I started on the Apollo Project)

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:41AM PDT (-0700 GMT)
Paul: I believe scientists are now saying conclusively that there is a magnetic field, because of G2 flyby results. Most science coordinators are in a meeting right now, but as soon as they get out I'll grab a mag field person and get them to answer conclusively.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:41AM PDT (-0700 GMT)
Re Ganymede's magnetic field, I heard at least one argument that said it would be tough to generate the observed field strength with a remnant magnetic field, and therefore the dynamo theory is somewhat more likely.

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 9:42AM PDT (-0700 GMT)
Hi, sorry to be late but I just got out of a project staff meeting. You can imagine how long *those* take sometimes. I'm Jim Taylor, and I work on the Orbiter's radio, telemetry modulation and command detection, and antennas. Also I work with the people in the Deep Space Network (DSN) who have the transmitter that sends to us and the receivers that get our data. It's raining outside here, and if that keeps up at Goldstone in the California desert, it will affect our "downlink" when the Goldstone station starts tracking us in about three more hours. We engineers sometimes keep our noses to pretty narrow grindstones. I look forward to learning about some of the Galileo science on this chat. Ready and listening.... Jim T.

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 9:42AM PDT (-0700 GMT)
I'm not sure where I fit in the Team intro's. I'm a science teacher/systems engineer. I teach Earth Science in New Jersey and still work on Galileo remotely. I formerly was group lead for the Scince Systems Engineering Group which develop a suite of planning tools for Galileo orbital operations. I left JPL 1 year ago to teach.

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 9:43AM PDT (-0700 GMT)
I'm Todd Barber, propulsion engineer, and have worked on Galileo for 6 years. My hobbies are planning basketball and tennis, singing in an a cappella jazz quintet and a church choir, playing the piano, and composing music.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 9:43AM PDT (-0700 GMT)
Well, lets see. I design and write flight software for the Galileo Control and Data Subsystem (CDS). Thats the computer that has the majority of changed software in order to support the low gain antenna mission, so I here I mostly just work on that. I went to college at UCI. Contrary to public belief I do not just sit in my dark office drinking Jolt Cola. They let me out on many weekends and I don't like Jolt. In my copious spare time I read science fiction and run a small old style D&D on paper dungeon.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:44AM PDT (-0700 GMT)
Bartman: When Galileo was designed back in the late 70's, radars and such were (and still can be) too massive for their worth, so it was left off.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 9:44AM PDT (-0700 GMT)
Hi Gerhard, If you look at the NIMS Ganymede Image now on the Galileo web page you can see that the surface is not entirely ice. NIMS has uncovered a 4.25 micron feature which could potentially be hydrated minerals. We are still narrowing down the candidates (There are many more than in this upcoming Presidential election.)

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 9:45AM PDT (-0700 GMT)
Good morning chatters! At 10 AM PST we will hopefully have a gallery of pictures of some of the people that you are chatting with on the webchat page (button

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 9:45AM PDT (-0700 GMT)
Jim T: How does rain effect our ability to track Galileo?

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 9:46AM PDT (-0700 GMT)
Hi Paul. Good to "see" you!

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:47AM PDT (-0700 GMT)
The G2 mag and plasa wave results were just what one would expect if Ganymede had it's own magnetic field. BTW I rememeber the conversation in the halls right after the G1 encounter and people were basically STUNNED. Finding a mag field at Ganymede was NOT expected by anyone but a fringe few. Ganymede was supposed to be a cold iceball. It's a tremendous result and will have a profound impact on our understanding of moons and their structure.

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 9:48AM PDT (-0700 GMT)
Let me do that again - I made a typo! The picture gallery will be here button

Nancy Vandermey,SEQ-Systems: . . . . Wed, Oct 30, 9:48AM PDT (-0700 GMT)
John Aiello had a lot of fun taking the team pictures yesterday on his personal toy, a Casio digital camera.

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 9:49AM PDT (-0700 GMT)
Informal chat stuff- I graduated from Cornell univ. (supposed school of Carl Sagan); lead/teach children's choir, sunday school & worship on weekends; & am an avid computer-user (one of the rare people who carry around a subnotebook laptop computer to meetings taking meticulous notes)...

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 9:51AM PDT (-0700 GMT)
Time for another propulsion fun-fact! Despite the seemingly exotic nature of our propellant combination (again, monomethylhydrazine and nitrogen tetroxide), the gases leaving the Galileo engines after firing are much more familiar. The primary products of combustion are carbon monoxide, carbon dioxide, hydrogen, nitrogen, and water.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 9:52AM PDT (-0700 GMT)
Hi, I'm Shadan Ardalan. A currently have a split personality disorder: part of me works with the Orbiter Engineering Team (like Steve Collins & Todd Barber), but another part of me works on the Sequence Team (like Nancy Vandermey & Leo Cheng). But all of me supports the Attitude & Articulation Control Subsystem. I'm most recently from Indianapolis, Indiana and attend Purdue University for my degree in Astronautical Engineering. For my free time (which is getting to be less and less), I cycle, play racquetball, hike, and play with my two dogs. If you are interest in reading more about me, check out my bio at a href="button

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 9:52AM PDT (-0700 GMT)
Intro: I'm one of NIMS science coordinators and have been with Galileo since Oct 1988. I'm originally from DownEast Maine, transplanted to CA in 1978. Outside of work, I spend my time painting, playing recorder and psaltry, and digging up family roots and skeletons.

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 9:53AM PDT (-0700 GMT)
My name is Laura Barnard and I like to think of myself as the Jill-of-all-trades here in the Galileo Science and Sequencing Office! I test & document software, run models of the tape (DMS) on the S/C, archive all of our planning sequences, corral volunteers for Outreach, and I am the main social director of the team. By that - I mean that I plan and organize all of our social events for the team, such as encounter parties and holiday games.

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 9:54AM PDT (-0700 GMT)
Speaking of propellant: how is the propellant margin holding up?

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 9:54AM PDT (-0700 GMT)
Hello all. I test(and fix) Tal's CDS code. In the real world I read science fiction, play D&D and MUDs, raise 2 boys, and try to figure out where all the time goes. I've worked on Galileo off and on since 1978.

Likelike schoolanonymous: . . . . Wed, Oct 30, 9:56AM PDT (-0700 GMT)
is it ok for some third graders to ask you questions

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 9:56AM PDT (-0700 GMT)
Paul, propellant margin is looking very good. If Lou D'Amario is still on line, I'm sure he will have more details for you. It appears very likely that there will be usable propellant remaining following the completion of the primary mission.

Bartman: . . . . Wed, Oct 30, 9:56AM PDT (-0700 GMT)
Has there been any thought of using ground-penetrating radar on subsequent missions to say, look under the ice on Europa? I realize that it may be difficult to see that far underground (under-ice), but it may be possible.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 9:56AM PDT (-0700 GMT)
Paul: Propellant margin has been improving - mainly due to converting science turns to unbalanced mode and good tour navigation. Our current estimate for PM is 22.7 kg. There is also 13 kg of Project Manager Reserves.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 9:57AM PDT (-0700 GMT)
Yes Likelike go for it. thats why we're here.

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 9:57AM PDT (-0700 GMT)
SPOT is an acronym for Science Planning and Operations Team. We are a small team of 16 people that coordinate and implement the science coordinators plans for the S/C. On any given day we are working three or more sequences. Because I planning AND archiving of past sequences I am now working on SIX sequences! Whew.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 9:57AM PDT (-0700 GMT)
Likelikeschool Ask Away!

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 9:57AM PDT (-0700 GMT)
Yes, 3rd graders are most welcome! Please ask away....

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 9:57AM PDT (-0700 GMT)
Hi Likelike, Third grader questions are definitely welcome!! They're my favorites.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 9:58AM PDT (-0700 GMT)
go ahead Likelikeschool and Todd: thanks for jumping in...I don't mind at all

Gerhard, Vienna, Austria: . . . . Wed, Oct 30, 9:58AM PDT (-0700 GMT)
Thanks, Marcia. I just had a look on the NIMS Ganymede map, you mentioned. A question maybe for somebody of the camera team: Was there time to take any measures concerning the big differences in light intensity on Ganymede close ups on the G2 encounter? As far as I know, it was quite difficult to get such an close up image because of the contrast between light and shadow.

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 9:59AM PDT (-0700 GMT)
Bartman, I don't know of any plans, but radars on earth are used to penetrate a few km below the icecaps in Antarctica. Mars 96, the Russian mission, has a very powerful and long wavelength radar on it. If the ice is only a few km thick on Europa it should work.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 9:59AM PDT (-0700 GMT)
From a guy who watched Viking, Voyager and read about Galileo, I just want to say that it's indeed a great pleasure to be given the opportunity to work with people like Dan...wow since 1978. Boy, I was in the 6th grade at the time!

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 10:00AM PDT (-0700 GMT)
Bartman, I'm not sure about the ground-penetrating radar, but there has been some talk about a Europa submarine to navigate a possible sub-surface liquid water ocean! Obviously, that mission is a few years off, and it would be predicated on finding a sub-surface ocean. There has been talk of a Europa orbiter mission as a follow-up to Galileo (I believe this was mentioned). I'm sure that detecting a possible sub-surface ocean would be VERY high on the priority list for that mission.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 10:00AM PDT (-0700 GMT)
Makes ya feel old don't it Dan?

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 10:02AM PDT (-0700 GMT)
Laura, you get credit for Jilling this webchat and for taking those pictures of us with that nifty digital camera yesterday. I'll have to see how I came out when I get a moment. Leslie, you asked how rain affects our downlink. Two ways: first, the signal is actually weakened as it passes through the part of the atmosphere where it's raining. That's called attenuation, and for the S-band frequency we use, that's the smaller of the two effects. The other way the rain affects our capability is by making the radio temperature the ground antenna sees higher. How much higher? Well, when it's not raining, our most sensitive receiver at the Canberra (Australia) station has a noise temperature of 13 kelvins. When it rains, pouring kangaroos and koalas I guess, that temperature can easily double. Doubling is serious trouble, because we plan our downlink data rates with only about 20% margin at times!

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:02AM PDT (-0700 GMT)
I think alot of us here have bios with "Online from Jupiter" (e.g., Todd, Steve, Leo, Laura). BR It might be good if you guys would provide the URLs so that our guests may likn to them.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 10:03AM PDT (-0700 GMT)
Now, now Tal...I'm sure you're up there too ;)

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 10:03AM PDT (-0700 GMT)
Gerhard: the camera folks are in a meeting right now, but I can tell you that the problem was indeed with the unexpected contrast, and that the sequences were corrected for future studies.

Bharat Parekh: . . . . Wed, Oct 30, 10:04AM PDT (-0700 GMT)
Hi everyone: I am a biochemist with losts of interest in planetary science. I try to keep up with developments regarding Galileo. Can someone explain to me why jovian moons are so different from each other? For example, Io is so hot and volcanic while Ganymede is icy and very cold. What could cause such drastic difference on local geology and environment? Also the presence of water (or hot water) and oxyzen on some of the planets is very exciting. It would be interesting to find out if some form of life (possibly quite different from here) could exist on planets with ice/water.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:04AM PDT (-0700 GMT)
In 1978, I was in 4th grade

Matt Webb Rutger U.: . . . . Wed, Oct 30, 10:04AM PDT (-0700 GMT)
is ther anybody on right now?

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 10:04AM PDT (-0700 GMT)
The pictures in the 'volunteer gallery' are GREAT!! You'll have to cover us science types too one of these days...

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:04AM PDT (-0700 GMT)
Bartman - I can't speak for the scientists and NASA, but the technology and the ideas are there. I am currently taking a Flight Science Instruments class here at the Lab, and one of the long range plans for NASA is the Solar System Roadmap that has "Portrait Missions". A majority of these missions are in situ (i.e. send probes, rovers, and aerobots). Most of the Radar technology is used in the Earth Sciences instead of Deep Space.

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:05AM PDT (-0700 GMT)
Thanks Leo, and I worked on Voyager and Viking. And a little on Mariner '71, a Mars Orbitter.

Katharina, Vienna, Austria: . . . . Wed, Oct 30, 10:05AM PDT (-0700 GMT)
Hello, I´m Katharina, a student from Vienna, Austria. I would like to ask, if we already can say, which materials are thrown out of the volcanoes of Io ? Is it sulphur compounds, or sulphur, or molten stone, or don´t we know it yet ?

Tal Brady..Flight Software: . . . . Wed, Oct 30, 10:05AM PDT (-0700 GMT)
Since 79 -- Dan Hired me onto Galileo. Did Galileo software, then Magellan, then Craf/Cassini then back to Galileo just before the antenna didn't open.

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 10:07AM PDT (-0700 GMT)
1978- it seems after working ~4.5 yrs on galileo, i'm still one of the young 'uns, being in 2nd grade over in ENgland that year; BTW, Laura- RU going 2 come down 2 the 5th floor w/ the digital camera again sometime this morning?

Matt Webb Rutger U.: . . . . Wed, Oct 30, 10:07AM PDT (-0700 GMT)
i ha d aquestion concerning the probe dropped into the jovian atmospher. Was there any video feed from that probe, and if so where might i find it on the web

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 10:07AM PDT (-0700 GMT)
Hi Gerhard, Unfortunately I can't give you a good answer to your question. However, I will pass it on to a SSI team member and hopefully have an answer for you by the end of this chat.

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:08AM PDT (-0700 GMT)
LikelikeSchool: Today's third graders might be the first people to live in a moonbase.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 10:08AM PDT (-0700 GMT)
Ashwin: Thanks for joining us! All our science coordinators here at JPL are in a meeting at the moment. Can you answer Katharina's question?

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 10:08AM PDT (-0700 GMT)
I have a question for the science teams. When will an Amalthea image be available? (Amalthea is an irregularly shaped small moon, inside Io's orbit, that is very red in color and was imaged by Voyager nearly 20 years ago).

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:09AM PDT (-0700 GMT)
Matt Webb Rutger U: Sorry, the probe had no camera.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 10:10AM PDT (-0700 GMT)
Hi, Matt No unfortunately there was no camera on the probe. I think that when we built Galileo they were to big heave and power hungry. There will be optical devices on the Cassini probe when it drops on Titan

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:10AM PDT (-0700 GMT)
Jeff - It is really difficult to change the pages once the chat session has started. I will try to get your picture in!

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 10:10AM PDT (-0700 GMT)
Matt - there was no video feed because that would require a huge amount of downlink (bandwith). There were quite a few instruments, however, some of which were sensitive to light. The Net Flux Radiometer, for example, measured how much light was going down and how much heat was coming up and in that way was able to 'see' cloud layers going by. There is probably a probe results page at the NASA AMES home page.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 10:10AM PDT (-0700 GMT)
Matt: No camera was on the probe - camera's are very data intensive, and for a study of the atmosphere, better data could be obtained from the 7 types of instruments that were selected. Have a look at button for info on the probe!

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 10:11AM PDT (-0700 GMT)
I guess that's one of the "advantages" of having a long mission. One gets to work on a project that you've read about as a teenager reading science magazines. I certainly appreciate it.

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 10:12AM PDT (-0700 GMT)
Katharina, (Vienna, Austria): I think they had some idea what the Io volcanoes spew out; it is obviously very different from any earth molten lava; i believe ammonia (NH4?) might be part of the mix, as well as icy mist that freezes and drops back to the surface, causing a geyser-like effect...

Jan Ludwinski, Mission Planning Office: . . . . Wed, Oct 30, 10:13AM PDT (-0700 GMT)
I believe the Galilean moons experienced very different environments during their early years a few billion years ago. Back then Jupiter was MUCH hotter than it is now. That heat drove away the light elements and compounds (like water) from Io, leaving it a mostly rocky body. Europa was heated to a lesser extent since it is farther from Jupiter, and it has only a thin crust of water, while Ganymede and Callisto (further yet) have a large amount of water ice inside them.

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 10:13AM PDT (-0700 GMT)
Regarding Katharina's question - not my expertise but I'm pretty sure that there are two types of material thought to be erupting. One is S02, sulfur dioxide, which then forms the white frosts on IO's surface. The other is basalt, like in Hawaii. You can see the black flows coming from the Volcanoes on some images - that's basalt.

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:13AM PDT (-0700 GMT)
Chatters - Please be patient with us! Or server is updating SLOWLY, and several of our experts are extremely busy this week. Several of the scientists are on travel, so we have a skeleton crew that comes and goes as they do their daily work. We are also preparing for our third encounter. Tomarrow we uplink the commands for Callisto 3 (C3), with the closest approach on Monday.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:14AM PDT (-0700 GMT)
Good question, Katharina!!!!BR Unfortunately, being in mission operations, I don't really know the answer. But by the look of the plumes, I almost think that methane is being erupted. Here's a link to the imagae I am referring to, button

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 10:15AM PDT (-0700 GMT)
Hi Katharina, NIMS is still in the process of analyzing the Io data but there are features in the spectra that reveal so2 frost. We still have lots of work to do. Thanks for the question.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 10:17AM PDT (-0700 GMT)
Katarina, You can tell by looking at the infrared pictures of Io, that there are some active regions that are very hot and probably are from silicate vulvanism (molten rock) and others that are active but at a much lower temperature these are probably areas where there is sulphur vulcanism. Also, the bright colors of Io are probably from different sulphur compounds. Clearly sulphur plays a key role in Io Geology

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 10:18AM PDT (-0700 GMT)
Hi Todd, Amalthea is a small satellite target for C3.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 10:19AM PDT (-0700 GMT)
Hello - is there anyone out there with a navigation or trajectory question. We navigators are feeling neglected.

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 10:19AM PDT (-0700 GMT)
On many images of Io, the black flows are the most recent flows of sulfur (probably pure and as various compounds including SO2). The reason they look black is that is the color of molten sulfur. It turns to orange and yellow as it cools. Some of the folks at Arizona State University of study this a fair bit (Ron Greely et al.)

John: . . . . Wed, Oct 30, 10:20AM PDT (-0700 GMT)
I loved the NIMS image of Ganymede, but which orbit was it taken on (G1 or G2). Also, what was the approximate resolution (or is it difficult to make a comparision to SSI images in that manner?)? So far I get the mipression that NIMS only takes "far away" images. Are there any plans for some real close up shots?

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 10:21AM PDT (-0700 GMT)
I do hope we'll get some questions from you 3rd graders... Don't be worried about them sounding too easy. That's why we are here...

Steven Tyler, Systems Engineer: . . . . Wed, Oct 30, 10:21AM PDT (-0700 GMT)
Katarina, there's about twice as much oxygen near Io as sulphur, so that's more consistent with sulphur dioxide than just sulphur.

Likelike schoolanonymous: . . . . Wed, Oct 30, 10:21AM PDT (-0700 GMT)
third grader, How big is the Red Spot?

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:22AM PDT (-0700 GMT)
There is a long chain of people involved in space exploration, in particular, and science, in general. This chain goes back to even before that Italian guy first trained a telescope on the heavens. Who was that anyway? ;-) I was in 8th grade when Sputnik was launched and just entering high school when the first US satelite Explorer I was launched.

jim: . . . . Wed, Oct 30, 10:22AM PDT (-0700 GMT)
What will be the eventual fate of Galileo? Will it remain in Jupiter orbit forever??

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 10:22AM PDT (-0700 GMT)
Nav Q) OK, lou, so- a question that I can inform people on JPL tours: "How accurately/precisely do we know the location & velocity of Galileo at any given point in time? What order of magnitude is the precision?"

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 10:22AM PDT (-0700 GMT)
Lou: How close will Galileo be coming to Callisto next Monday?

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 10:23AM PDT (-0700 GMT)
Likelike schoolanonymous: The Great Red Spot on Jupiter is _very_ big. So big that you can fit 2 Earth's side by side. Can you imagine that!

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 10:23AM PDT (-0700 GMT)
GOOD NEWS! THe science folks are out of their meeting, so they should be on line shortly to answer more questions...!!!

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 10:23AM PDT (-0700 GMT)
For you Nav folks: how are we looking for extended mission? How long will the propellant last given the current plans?

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:23AM PDT (-0700 GMT)
Lou - How many times do you check your math? ;-) Do you trust the computers or do you do the navigation manually at least once to double check?

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 10:24AM PDT (-0700 GMT)
Katharina, mein Name ist Fritz Krug, ich bin Todd's Gruppenleiter. Ich weiss nichts ueber die chemische Zusammensetzung der Stoffe, die aus den Io Vulkanen ausgeworfen werden. Aber ich dachte es ist "fun," wenn ich Dir in deutsch antworte. Todd und ich sind bei Galileo beschaeftigt als "propulsion analysts," das heisst wir analysieren alle Aktivitaeten der kleinen Galileo-Triebwerke. Der Grund warum ich hier arbeitete ist, weil das gesamte Antriebsmodul von Galileo in Deutschland hergestellt wurde. Todd ist besser informiert, was auf der wissenschaftlichen Seite vorgeht, deshalb gebe ich jetzt an weiter.

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 10:24AM PDT (-0700 GMT)
GreatRedSpot: one of the simplest comparisons- about 3 earth's can fit within the GRS.

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 10:24AM PDT (-0700 GMT)
Hey a JUpiter question!! Well, Likelike, the Red Spot is huge. You could easily fit two Earth's side by side in it. It is 20000 km wide by 10000 km (something like 12000 miles by 6000 miles).

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 10:24AM PDT (-0700 GMT)
Likelike schoolanonymous: Hi 3rd grader! What state are you talking to us from?

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:25AM PDT (-0700 GMT)
I have plenty of questions for you, Lou. ;-) Like did we get useable OPNAVs of Callisto for this most recent orbit determination.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 10:25AM PDT (-0700 GMT)
Galileo will fly by Callisto on Monday at an altitude of 1110 km +/- 38 km

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 10:25AM PDT (-0700 GMT)
jim: There are 3 possibilities. The most likely occurrence is that after several hundred to a thousand years, Galileo will impact a moon of Jupiter. A less likely outcome is that Galileo will reenter the atmosphere of Jupiter. The least likely outcome is that Galileo will escape the Jupiter system.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 10:25AM PDT (-0700 GMT)
Duane: are you back on line? We've had several magnetic field questions about Ganymede!

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:26AM PDT (-0700 GMT)
Wow - Lou asked for a question and got several? How about me? Doesn't anyone want to know how to make science coordinators AGREE on a sequence, fly it, and archive it?

Katharina, Vienna, Austria: . . . . Wed, Oct 30, 10:26AM PDT (-0700 GMT)
Thanks for the interesting answers about Io. Ashwin, as you work with atmospheric science, can you tell me something about thunder and lightning in Jupiter´s atmosphere ? Are we sure both exist on Jupiter, and did the Galileo probe confirm their existence ?

Tal Brady..Flight Software: . . . . Wed, Oct 30, 10:27AM PDT (-0700 GMT)
A little note for Likelike... Galileo was launched just about a year after you were born, if I'm counting right. The computer that I work on is probably about the same size (the box it fits in) as the computer that you're using to talk here, but it has much less memory to run programs. It has no vidoe display. In fact it just talks to us in numbers (called downlink or telemetry) over the radio. It has a tape recorder in stead of a disk, but programs are not stored on the recorder, only science data. Also it is much much slower than your computer. Think of the difference between a humming bird and a snail and you will just about have an idea of how slow. And it can't multiply divide or do fractions either. Hope you hav a Happy Halloween! Its my favorite holiday.

Likelike schoolanonymous: . . . . Wed, Oct 30, 10:27AM PDT (-0700 GMT)
Likelike School, third graders, Marcelo Tellez-How long and how big is Jupiter? Ryan Ramelb-Who was the first scientist to discover Jupiter? Kathrina Guira- How will we breathe on Mars? Keone Villaplaza-How heavy is Jupiter? Matthew Madela-How did Jupiter get it's ring?

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 10:28AM PDT (-0700 GMT)
You can't make science coordinators agree

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 10:28AM PDT (-0700 GMT)
Laura, if we knew the answer to that question, we wouldn't need to have any integration meetings, or science planning meetings, or office meetings or ... hey, we wouldn't have a job!

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 10:28AM PDT (-0700 GMT)
GLL fate- Yet another possibility is that w/in a century, 2nd-generation ion-propulsion etc. will be developed, & Galileo will be "retrieved" to see what really happened to the stuck high gain antenna. :-)

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 10:29AM PDT (-0700 GMT)
Hi John, The NIMS G2 Ganymede observation is about 115 km resolution. NIMS has taken high resolution shots of Ganymede as well. These have not been released yet. SSI spatial resolution is 50 times greater than NIMS but NIMS is a spectrometer with 408 color capability. I'm glad you love the image, look for more in the near future.

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 10:29AM PDT (-0700 GMT)
Katharina, finding lightning and thunder on Jupiter is important mainly because we are desperately looking for water. Water, of course, is important for many reasons, including that is transports energy very effictively. On earth, 'moist convection' in thunderstorms powers our atmosphere. Voyager found lightning at certain locations. Galileo Probe detected lightning far off, but not near the probe entry site, consistent with it being a dry region.

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:29AM PDT (-0700 GMT)
Lou - Could we potential become a probe? Just before we die of lack of resources or radiation could we plumet into Jupiter or one of the moons?(like Magellen for example)

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 10:30AM PDT (-0700 GMT)
Jeff Chung: We can predict the future position of Galileo with respect to a satellite like Ganymede to within a few 10s of kilometers. We can predict the velocity to within milimeters per second. After a satellite encounter has occurred, we can reconstruct the position to within a kilometer or less.

jim: . . . . Wed, Oct 30, 10:30AM PDT (-0700 GMT)
to Lou D'Amario, Galileo Navigation: Strange ... that Galileo could ever escape the Jupter system without extra "umph". Slingshot principle, I guess.

Tal Brady..Flight Software: . . . . Wed, Oct 30, 10:30AM PDT (-0700 GMT)
Have to sign off now for one of my meetings...Hopefully I'll be back before this is over.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 10:31AM PDT (-0700 GMT)
Laura - on the math thing. Never, ever, is it right to say "That's the answer because it came out of the computer", we sit around a lot at lot at answers many different ways to be sure that we believe them. We do "gut check" or reasonability checks quite often.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 10:31AM PDT (-0700 GMT)
Marcelo Tellez: Jupiter is the largest planet in the solar system. You can fit 11 earth side by side across Jupiter.

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 10:31AM PDT (-0700 GMT)
Okay, for a power person: one of my students, Ian, wants to know how long Galileo will continue to have electrical power

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:31AM PDT (-0700 GMT)
jim: the eventual fate of Galileo will be determine by Congress (believe it or not). The mission planners are proposing an extened mission following the end of the prime mission (at the end of 1997). The extended mission, called the Galileo Europa Mission (GEM), will do about a half-dozen addition flybys of Europa, then about another half-dozen flybs of Callisto in order to lover its perijove (point of closest approach to Jupiter) so that we can have atleast one flyby of Io. I don't know what the status of the GEM proposal is currently; My guess is that it won't be decided on until the next Congress is in session, January 1998.

Katharina, Vienna, Austria: . . . . Wed, Oct 30, 10:32AM PDT (-0700 GMT)
Danke, Fritz Krug, fuer Deine nette Botschaft !! Es war wirklich erstaunlich, ploetzlich deutsche Worte aus Californien gesandt zu bekommen. I think, I´ll write the rest in English, for the others cannot understand German language. Fritz, are there many people from Germany currently working on Galileo at the JPL ?

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:32AM PDT (-0700 GMT)
jim: the eventual fate of Galileo will be determine by Congress (believe it or not). The mission planners are proposing an extened mission following the end of the prime mission (at the end of 1997). The extended mission, called the Galileo Europa Mission (GEM), will do about a half-dozen addition flybys of Europa, then about another half-dozen flybs of Callisto in order to lover its perijove (point of closest approach to Jupiter) so that we can have atleast one flyby of Io. I don't know what the status of the GEM proposal is currently; My guess is that it won't be decided on until the next Congress is in session, January 1998.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 10:32AM PDT (-0700 GMT)
jim: The way Galileo could escape the Jupiter system is by a combination of fortunate satellite flybys that increase orbital period plus fortuitous effects of solar gravity that would increase the spacecraft energy and pull it away from Jupiter,

Ashwin Vasavada, SSI Atmospheric Science: . . . . Wed, Oct 30, 10:33AM PDT (-0700 GMT)
Katharina, there will be additional lightning searches on Jupiter by the Galileo orbiter next month. The camera (SSI) will leave its shutter open and slew across the planet. If lightning strikes during the long exposure, we'll see it. Thunder, however, should happen but we wont hear it.

Jan Ludwinski, Mission Planning Office: . . . . Wed, Oct 30, 10:33AM PDT (-0700 GMT)
You can fit about 1400 Earths inside of Jupiter!

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 10:33AM PDT (-0700 GMT)
Hi Laura, Yes, I want to know... I agree with Paul, you can't get them to agree.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 10:36AM PDT (-0700 GMT)
It would be quite difficult to make the Galileo orbiter impact Jupiter at this point. The GEM mission after doing 8 Europa flybys will use Callisto flybys to lower the closest approach down to the distance of Io, but the radiation is rapidly increasing and that is only at 5.9 Jupiter radii. To get down to the surface would not be possible with an operating spacecraft.

Likelike schoolanonymous: . . . . Wed, Oct 30, 10:36AM PDT (-0700 GMT)
Ashwin Vasavada, Leslie Lowes, Tal Brady, Likelike School is in Honolulu, Hawaii. Thank you for answering our questions. More to follow.

Jim Erickson, Science & Sequence Office: . . . . Wed, Oct 30, 10:37AM PDT (-0700 GMT)
Back on-line now.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:37AM PDT (-0700 GMT)
jim: Lou explained Galileo's fate as dictated by physics. I explained Galileo's fate as dictated by Congress. Hmmmm, Congress vs. Physics...I wonder who will win that battle??? ;-)

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:37AM PDT (-0700 GMT)
Katharina - We currently have a PPR science coordinator that is a German Citizen. He is currently visiting his family in Berlin. We also have affiliates and investigators that are all over the world including Germany.

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 10:38AM PDT (-0700 GMT)
Likelike, I'll bet you're in Hawaii. I remember there's a highway by that name on Oahu. My sister is the librarian of the Kaneohe branch of the state library system. She likes it that she doesn't have to take so much time getting to work as when she commuted to the Waikiki branch. Your questions about Jupiter are good. I'm not smart enough on the computer just to give you a "button" to look up the stuff. For instance, Jupiter is almost 90,000 miles across. That's more than 10 times as wide as the earth. By the way, I'm also one of those who was working on Galileo long before you third graders were born. I started on this project in 1979, working with the radios and antennas then. Before that, I worked on the Viking Orbiter project. It was a great thrill to be here that early morning in July 1976 when the first Viking Lander touched down safely on Mars. We were all holding our breaths, hoping it would make it safely. I still remember the shouts and whistles, and the more quiet sighs of relief, and how we all shook hands with the people around us. Quite a day! yourself, so I'll try to find it for you the old-fasioned way, by reading it from a book!

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:38AM PDT (-0700 GMT)
Matt Webb Rutger U: Sorry, the probe had no camera.

Steven Tyler, Systems Engineer: . . . . Wed, Oct 30, 10:38AM PDT (-0700 GMT)
Last time we had a chat, there were a couple of questions about Jovian aurorae. Doesn't anyone want to talk about aurorae now that Jovian satellite aurorae are becoming an issue?

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 10:39AM PDT (-0700 GMT)
Ryan Ramelb: Many ancient peoples, the Greeks, and Chinese among others, thousands of years ago noticed that by looking night after night at the stars, that some "stars" move against the night sky. They called these stars "planets" or "wandering stars". But it took the invention of the telescope, and Galileo's desire to look at one of the planets, Jupiter, and see that they are not pinpoints of light, but are little balls of light. Galileo also discovered that Jupiter had moons circling it. This was a great breakthough because he realized that Jupiter, was just like the earth, since it had moons. Hope that helps.

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:39AM PDT (-0700 GMT)
You make science coordinators agree by sneak attacks and stuffing them full of Halloween candy!

Gerhard, Vienna, Austria: . . . . Wed, Oct 30, 10:40AM PDT (-0700 GMT)
I have read about the hypothesis of "water volcanoes" on Ganymed. Did Galileo as yet give any indications that there is any active or recent water volcanism on any of Jupiter´s moons ? (And if anyone knows: I think I read they found something like geysirs on the Neptune moon Triton ? Does anyone know if this is just a theory, or a confirmed observation ?

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 10:40AM PDT (-0700 GMT)
Any answers on how long Galileo will have power?

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 10:40AM PDT (-0700 GMT)
Shadan - That is a no brainer! Congress and NASA will win - even if we could somehow prove to them something could make money!

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:41AM PDT (-0700 GMT)
Keone Villaplaza: Jupiter is over twice as massive as all of the other planets combined!

Jan Ludwinski, Mission Planning Office: . . . . Wed, Oct 30, 10:43AM PDT (-0700 GMT)
It's interesting to note that Galileo has international science partners from not only Germany, but Canada, Great Britain, France, and Sweden. And the Galileo is monitored from antennas (really big satellite dishes!) in California, Spain, and Australia.

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:43AM PDT (-0700 GMT)
Paul Fisher: Since Galileo is powered by radioactive decay of plutonium, its power will drop off gradually.

Leslie Tamppari PPR: . . . . Wed, Oct 30, 10:44AM PDT (-0700 GMT)
Hi, I'm here to participate after the morning meeting....

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 10:44AM PDT (-0700 GMT)
PaulF- i think power lifetime is a function of the RTG's deteriorating in output.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:44AM PDT (-0700 GMT)
Katharina: I don't know if Fritz answered your question about Germans, but I will try to anyway. Galileo's main engine was built in Germany. Besides Fritz, we are also fortunate enough to have Klaus-Peter Renner working with him & Todd Barber.

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 10:45AM PDT (-0700 GMT)
Gerhard, I'm not sure what the latest is on Ganymede. Our geologists are all in Boulder for a national meeting. Stay tuned to future web chats. Regarding Triton, those plumes were real, that is they were observed. The heights were measured from images and the directions of the plume 'spray' was predicted by atmospheric theory (basically it is carried by winds off of the polar cap). The geysers may be due to material liquifying or evaporating under a layer of ice and then bursting through.

ModemGuy: . . . . Wed, Oct 30, 10:45AM PDT (-0700 GMT)
hello everybody. The galileo page said we'd get a new picture 5 days a week. where are the last 3 days' worth of pictures?

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 10:45AM PDT (-0700 GMT)
Since the RTGs have been installed for a *long* time is there an estimate for when the power will decay to the point that it is not possible to keep all the systems operating?

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 10:47AM PDT (-0700 GMT)
Katharina, the net language is English, you're right. Ok, yes there are two employees of DLR, the German Research Establishment for Air- and Spaceflight, working here at JPL. We are so called residents supporting the operation of GLL. In addition to that, there is German participation of unversities and other research organizations in (I think) seven out of the 19 or so science instruments flown on GLL and its (now deceased) probe. These institutes are the Max-Planck Institut in Heidelberg und Katlenburg-Lindau and also DLR in Berlin and Oberpfaffenhofen (near Muenchen).

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 10:47AM PDT (-0700 GMT)
Hi Gerhard, We've not seen any indication of recent or active water volcanoes thus far. The same theory was suggested for Callisto as well.

Leslie Tamppari PPR: . . . . Wed, Oct 30, 10:48AM PDT (-0700 GMT)
Paul Fisher: I remember hearing that the original estimates were such that near the end of our Prime mission (Dec. 1997) we might have to cycle instuments off to turn others on. By the way, is your class participating or just you?

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 10:48AM PDT (-0700 GMT)
Hi, I'm ready to chat...Any questions out there?

Rebecca Westbrook, outreach: . . . . Wed, Oct 30, 10:50AM PDT (-0700 GMT)
ModemGuy: We are featuring other instruments' data this week, but we're low on staffing this week due to conferences, illnesses... we're working as I type on getting today's image out. Thanks for your interest, though! BTW, tomorrow we will have a new PPR temperature map of the Great Red Spot, and Friday we will have a UVS movie of aurora on Jupiter.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 10:50AM PDT (-0700 GMT)
Ryan Ramelb: Let me summarize my long answer to your question. Many ancient peoples discovered planets, but they didn't think that those planets were like the earth. They also didn't think those planets circled around the sun. Many thought they, including the sun, circled the earth. The idea that the planets, and the earth circled the sun took a long time to accept. Copernicus had proposed this idea, but it took Galileo and his telescope to show that these planets didn't orbit the earth, because he saw little moons orbiting Jupiter.

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:50AM PDT (-0700 GMT)
Paul Fisher: If there are any power folk on line, perhaps they could give us some projected wattage figures. My impression is that the natural radiation around Jupiter will probably cook our electronics before the power levels get low enough to cause us serious problems.

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 10:50AM PDT (-0700 GMT)
Paul Herrera: Can you tell us what NIMS has planned for the next orbit (C3)?

Oliver: . . . . Wed, Oct 30, 10:51AM PDT (-0700 GMT)
A hello from Germany!

tayfun: . . . . Wed, Oct 30, 10:51AM PDT (-0700 GMT)
Hi from Turkey. There was a question about the OPNAV images of Callisto. In one of the WEB pages it was said that OPNAV images were not succesful. Is there a problem about that?

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 10:51AM PDT (-0700 GMT)
I have about 10 people in the room right now.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 10:51AM PDT (-0700 GMT)
Leslie: What is PPR doing in C3?

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 10:52AM PDT (-0700 GMT)
Here's what coming up in the next few days (from a navigator's point of view). Tonight and tomorrow, the Flight Team will be designing the final pre-encounter trajectory correction maneuver. It is scheduled to be executed early Friday morning, but we may not perform the maneuver if the trajectory is close enough to the target without doing the correction. Then the Callist 3 encounter occurs on Monday, Nov. 1, with closest approach at 6:20 AM PST.

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 10:52AM PDT (-0700 GMT)
Hello Oliver. Any questions for us this morning?

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:52AM PDT (-0700 GMT)
PaulF: I would think that the radioactive decay of plutonium is very, very, very gradual. My guess is that radition is the primary cause for deteriorating power output from the Radioisotope Thermoelectric Generators (RTGs).

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 10:53AM PDT (-0700 GMT)
Oliver: A hello to Germany. One of our PPR employees is a German citizen and he's home in Berlin right now for vacation (returning later today).

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 10:53AM PDT (-0700 GMT)
Where is Jupiter in the sky these days. Is it the Morning Star or the Evening Star?

Jim Erickson, Science & Sequence Office: . . . . Wed, Oct 30, 10:53AM PDT (-0700 GMT)
Paul- I'll take a stab at the power question. We presently have about 485 watts being output from the RTG's, with around 10-40 watts being excess margin. By nominal end of mission were down to 470, and losing .6 watts per month. We'll have problems then, and will have to make further decisions what to turn off on the spacecraft. The RTG's will continue to put out power even after there isn't enough to keep the spacecraft all running.

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 10:53AM PDT (-0700 GMT)
Sure Leslie. Hang on a minute..

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 10:53AM PDT (-0700 GMT)
Correction - The Callisto 3 encounter is Monday, Nov. 4.

Steven Tyler, Systems Engineer: . . . . Wed, Oct 30, 10:53AM PDT (-0700 GMT)
Paul...Galileo power is decreasing slowly, and there will be plenty left even at the end of the proposed Europa Mission (8 Europa passes, 4 Callisto passes, and one or two Io passes). The only problem is that the craft has big power demands. We had about 570 watts at launch, have about 485 watts now, and will have about 460 watts at the end of 1999. At that point, we can't predict any further because our power program is suffering from the millenium bug... Even losing 20 watts is significant to operations, because it means we might have to turn off or cycle important heaters or even give up on an instrument by the end of 1999.

Likelike schoolanonymous: . . . . Wed, Oct 30, 10:53AM PDT (-0700 GMT)
Likelike School third graders-Marc DelaRosa-When are astronauts going to Jupiter? Derek Choi-Are there aliens living on Jupiter? Ramsay Carillo-What color is Jupiter? Andy Marques-Is Jupiter Red?

Oliver: . . . . Wed, Oct 30, 10:53AM PDT (-0700 GMT)
I was just looking around in the web when I found this. what do you discuss?

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 10:54AM PDT (-0700 GMT)
In addition to what Lou just told you, after the Callisto encounter on Monday there is an more distant but still close encounter with Europa on Wednesday at 11:36 am PST at about 34,000 km altitude which is much closer than we've been so far.

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 10:54AM PDT (-0700 GMT)
Paul Fisher, I don't believe we have any power analysts on the net today. But I can tell you that the RTG decay is one of the possible mission-limiting factors for Galileo. However, most recent projections suggest that we will run out of money, propellant, or "radiation tolerance" first.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 10:54AM PDT (-0700 GMT)
Oliver: Space exploration and the Galileo Mission in particular.

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 10:54AM PDT (-0700 GMT)
The international participation is really impressive!! As far as SSI goes, in C3 we cover a belt/zone boundary on Jupiter. Jupiter's atmosphere has two types of features - bands (belts and zones) and spots (vortices like the Great REd Spot). In G1 we saw the king of the spots, and now in C3 we see typical belt/zone region.

anonymous: . . . . Wed, Oct 30, 10:54AM PDT (-0700 GMT)
For Paul Herrera -- from Ray Fisher in Camp Hill, PA. I love 3d visual photos of space objects. Have you ever, or can you, make 3d images in the Near Infrared, and if you did, could you learn anything of value from them?

Oliver: . . . . Wed, Oct 30, 10:55AM PDT (-0700 GMT)
And what means PPR?

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 10:55AM PDT (-0700 GMT)
Leslie Tamppari: what is the status of PPR?

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 10:56AM PDT (-0700 GMT)
likelike school: If we send astronauts to mars, they'll have to take their own air with them. Or manufacture it there from ice. Mars has an atmosphere, but it is almost all carbon dioxide and is *very* thin. Thinner than the air on top of mount everest, so astronauts would still have to wear space suits on the surface of mars. Some people have imagined that you could build big domes on the surface, fill them with air and live in them someday

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 10:57AM PDT (-0700 GMT)
PPR is going to be observing the dayside and the nightside of Callisto and Europa in the C3 orbit. We will get temperature maps similar to the Ganymede dayside map that is already on the Galileo home page. These temperature maps will help us see if there could be water volcanos on Europa and will also help us determine the size of the rocks on the surfaces (boudlers or sand, for example). The PPR instrument will also look at Jupiter. In this orbit we will look (along with the other remote sensing instruments-NIMS, SSI, UVS) at a belt/zone boundary-in other words, in between the banded structure that Jupiter is famous for.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 10:57AM PDT (-0700 GMT)
Hi Gerhard, Answer from Jim Kaufman (Imaging Team) regarding your question about light intensity differences. Throughout the mission,we make modifications to the software that generates exposure times and gains on the camera based on prior data/orbits. Modifications were made to take into account greater than expected dynamic ranges in light intensity levels. This is an ongoing process from orbit to orbit.

Oliver: . . . . Wed, Oct 30, 10:58AM PDT (-0700 GMT)
Do you really think that one day we will send somebody on mars or on further outer space? How will he survive on journey?

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 10:58AM PDT (-0700 GMT)
Marc: There are no plans to send astonauts to Jupiter. There are still a lot of problems to be worked out, like how to protect them against the high radiaiton enviroment of Jupiter. I, for one, would love to travel in space. But we need to start with something we can do, like building a space station or lunar station, or going to Mars.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 10:59AM PDT (-0700 GMT)
tayfun: On approach to the Callisto 3 encounter, we are taking 26 OPNAV pictures. They are not always successful. Somtimes the camera is obscured by a rotating spacecraft boom. Sometimes the onboard software is not able to find the objects of interest in the picture. Sometimes, we have problems with the receiving antennas while the picture is being sent back from Galileo. So far, we have been very successful and have received 18 usable pictures of 24 taken to date.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 10:59AM PDT (-0700 GMT)
tayfun: the problem with the OPNAV images of Callisto is an age old problem that plaqued photographers forever...the images were underexposed.

Jeff Chung, CDS Analyst on SEQuence Team: . . . . Wed, Oct 30, 10:59AM PDT (-0700 GMT)
Astronauts: Keep in mind there is no known/definitive "land mass" on jupiter; like most of the "outer planets," jupiter is a gas giant, almost like the sun or other stars.

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 10:59AM PDT (-0700 GMT)
Regarding: aliens on Jupiter--thanks for the intriguing question! The current thought is that Jupiter itself would *not* be a good place for life to take hold. In particular, the dynamics of the atmosphere would make it very difficult for a potential life-form to be stable (imagine being baked in the heat, being shot up on a huge updraft of wind, and then having your temperature drop hundreds of degrees very quickly). However, one of Jupiter's moons, Europa, might just have the "right stuff" for alien lifeforms, since there may be liquid water there (a necessity for life, at least as it formed on Earth). Galileo will make its first very close pass by Europa on December 19th of this year.

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 11:00AM PDT (-0700 GMT)
Leslie, We're going to be doing a Real-Time Callisto observation, lots of Io observations. Also, NIMS will be covering the Asgard Basin and the multi ring structure. Furthermore, we'll be covering the Burr-Central Pit Crater. Europa will be covered in Real-Time as well as a Global Mosaic of Europa and we'll also be recording spectra on the Linea Region. Ahh yes! We'll also be doing a Main Ring observation i.e. Rings around Jupiter!!

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:00AM PDT (-0700 GMT)
Likelike school: Ramsay and Andy: Jupiter is a beautiful planet made of orange, white, and red bands and storms. The Great Red Spot is - guess what - red! Here's a link to a pretty picture of Jupiter: button

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 11:01AM PDT (-0700 GMT)
tayfun: Thanks to Shadan for reminding me. We lost several Callisto pictures because of the problem of predicting its brightness. Also, all the OPNAV pictures are not of Callisto - we use Ganymede, Europa, and Io also.

Jan Ludwinski, Mission Planning Office: . . . . Wed, Oct 30, 11:01AM PDT (-0700 GMT)
The RTG's are currently generating about 485 watts. The amount of power they generate is falling by about 8 watts per year, so we expect to have about 460 watts available at the time of the Io encounter in October 1999, provided the spacecraft is still operating. As Leslie said above, we may have to share some power between some instruments by then, but we expect most of them to be able to get enough power. Paul is also correct, that the very high radiation around Jupiter is constantly hitting Galileo (like an uncountable number of very small bullets, but made of electrons and atomic nuclei) is probably the greatest risk. Galileo was designed to last through its primary mission in Dec 97, and it could die anytime after that, although we are hopeful that it will make it all the way back to Io.

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 11:01AM PDT (-0700 GMT)
For an MWG type: why does Jupiter have a high radiation environment?

Gerhard, Vienna, Austria: . . . . Wed, Oct 30, 11:03AM PDT (-0700 GMT)
One of the most exciting things I read about Jupiter in the last few weeks was (if I recall it right) about the point in Jupiter´s atmosphere, where particles (?) (ions ?) from the Io flux tube bounce against Jupiter´s atmosphere and create a big circular region of aurora (I think several 100 or 1000 kilometers across ??). Did I understand it right ? And is this visible in visible light, or only in ultraviolet ? So, if I was floating somewhere down there in this stormy atmosphere, what would I expect to see ? (...if I was able to see anything despite chilling coldness, radiation and storms...)

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:03AM PDT (-0700 GMT)
MAG/DDS back online. I understand that there were questions about Ganymede's magnetic field. I'll try to summarize what we've learned in the next message.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 11:03AM PDT (-0700 GMT)
Likelike school kids: I see that you are from Hawaii. That's great, I grew up on Guam, an island in Micronesia! Just like you, when I was in the 3rd grade, I dreamed of traveling in space, and working for NASA.

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:03AM PDT (-0700 GMT)
Paul F and class: PPR has a stuck filter wheel. It is stuck in one of our radiometry (thermal) filters - 37 micrometers. We had 23 active filters that we planned to use, spanning the visible region and the far infrared, with the capability to do polarimetry as well (filtering out some directions of light like polariod sunglasses). We are still working on trying to fix the filter wheel to be able to use all the filters.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 11:03AM PDT (-0700 GMT)
Derek at likelike: There are no aliens living at jupiter that we know of. It's not totally impossible, though. There are some scientists who think that there may be a huge ocean under the ice of Jupiter's moon Europa. If there is, then it could be possible that there are wierd fish or other life forms that live there, just like the wierd tubeworms that live next to volcanic vents at the bottom of our ocean. There's even a conference in a couple of weeks to talk about the Europa ocean and how to explore it!

Voyager II, Trois-Rivières, Québec: . . . . Wed, Oct 30, 11:04AM PDT (-0700 GMT)
Hello! I see you away from deep space, :) and i wonder if we'll soon view the ganymede II photos taken by Galileo, at the closest approach? (on the web)

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 11:05AM PDT (-0700 GMT)
Oliver: NASA has a plan to send people to Mars one day. We're also in conjunction with the Russians. However, if this ever materializes or not is another question...

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 11:05AM PDT (-0700 GMT)
Oliver, Gruss Gott! I think we will head to Mars someday--it's only a matter of figuring out how to afford the trip. It is an expensive undertaking even with international cooperation. A trip to Jupiter is a much more daunting prospect. The trip time is much increased, there are unknown effects for years in microgravity, radiation shielding (both from cosmic rays and Jupiter itself) is a BIG issue, etc. It's not inconceivable that someday we may have human landings on some of the outer moons of Jupiter.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:05AM PDT (-0700 GMT)
Question for you CLASSES & EDUCATORS: How did you find out about this chat?

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:07AM PDT (-0700 GMT)
Gerhard, about the second part of your question - floating around in Jupiter's atmophere would probably look similar to flying in an airplane through clouds on Earth. There are cloudy bands where you wouldnt see much at all, and there are clear regions where you could see for miles. You would probably see a thin cirrus-like haze high above you. One difference is that on Jupiter you could actually fly so deep that sunlight no longer penetrates - this situation is more like the earth's oceans.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 11:07AM PDT (-0700 GMT)
Hi Ray in Camp Hill, NIMS technically can build up a 408d image of whatever it observes. This data serves numerous purposes. For Jupiter, cloud composition, height, and dynamics can be revealed. For the satellites, the data can tell us what the surface composition is, if it's ice or minerals. It can also give information about temperature.

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:07AM PDT (-0700 GMT)
The first passage of Galileo by Ganymede yielded some remarkable measurements of magnetic field strength (by the magnetometer) and some very interesting electric and magnetic field phenomenon (by the Plasma Wave instrument). These measurements suggested that Ganymede had a strong magnetic field associated with it, and that the magnetic field was behaving in ways that are very similar to the Earth's internally-generated magentic field. (continues...)

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:10AM PDT (-0700 GMT)
Voyager II: Hi! Some of the Ganymede 2 images are up on the web page now, and we'll continue to see them during the next few weeks. Did you have a look at button We have seen actual frost at the north polar area of Ganymede (and now they think we might be able to ski there! ;) ). We also have a very nice photo of a place on Ganymede were the light and dark areas overlap, The light regions are newer and have an appearance that resembles glaciated regions. The dark areas are older and have more craters.

Ray Fisher: . . . . Wed, Oct 30, 11:10AM PDT (-0700 GMT)
Thanks, Marcia. I said 3d. Maybe I should have been more explicit and said stereo pairs. What do you mean by -- a 408d image -- ?

Oliver: . . . . Wed, Oct 30, 11:10AM PDT (-0700 GMT)
Bye, I must leave you now. Thanks for this chat and have a nice day. Ciao

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:11AM PDT (-0700 GMT)
Gerhard, perhaps I should be a bit more dramatic... You would also see alot more color than on Earth -clouds of red, yellow, brown... The thunderstorms that we saw in G1 images would dwarf whatever clouds we have on earth - cumulus towers (thunderstorms) 30 km high! I wonder what a vortex like the Red Spot would look like from sideways on ... Don't fly too near.

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:11AM PDT (-0700 GMT)
Voyager II: There should be photos of the Ganymede 2 flyby already on the web. At least I saw on on the intro page this morning.

Voyager II, Trois-Rivières, Québec: . . . . Wed, Oct 30, 11:11AM PDT (-0700 GMT)
Oups, excuse-me, i don't remember this session is for classes and teachers, see you later!

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 11:11AM PDT (-0700 GMT)
To whomever asked about Jupiter's position: Jupiter is currently in the evening sky, pretty nearly straight south around sunset (or maybe somewhat west of that?). It is the brightest object in the sky after the Sun, Moon, and Venus (Venus is currently a "morning star" so there is no chance of confusion). Get your look at Jupiter now since it will soon be lost in the glare of sunset.

Likelike schoolanonymous: . . . . Wed, Oct 30, 11:12AM PDT (-0700 GMT)
Likelike School, Honolulu,Crystal-How does Jupiter look like in space? Siengsen-Why is Jupiter the biggest planet in the solor system? Phung-Why does Jupiter have the thin ring? Annie-Is there nature on Jupiter? Sara-Why does Jupiter have 16 moons?

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:12AM PDT (-0700 GMT)
For Paul Fisher: Jupiter has a very strong magnetic field. Such a field is capable of trapping very fast-moving (i.e., high-energy) ions and electrons. These particles emit radiation as they move through various parts of the magnetic field, or, in many cases, can cause radiation damage to anything that they might encounter themselves. In addition, the Jupiter system has at least two sources of small particles (which are broken up and ionized to make these ions and electrons). The two sources are the volcanos of Io and Jupiter's ring system.

anonymous: . . . . Wed, Oct 30, 11:12AM PDT (-0700 GMT)
hey, i thought we need more than just water for life to be created?

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:13AM PDT (-0700 GMT)
Voyager II: no need to go, but if you do, come back between 4 and 7 tonight PDT

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 11:13AM PDT (-0700 GMT)
Yoyager II - Come back! The session is open to everyone.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 11:13AM PDT (-0700 GMT)
Leslie: That should be PST, not PDT.

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 11:13AM PDT (-0700 GMT)
tayfun: We take many OPNAVs because there are unfortunate circumstances like Lou described which result in a "lost" OPNAV. Ideally, we would love to have every OPNAV we can get. By taking as many as possible, Lou & the NAV team increase the accuracy of the determination on the postion of Galileo. But also, by scheduling as many OPNAVs as feasible, we decrease the possiblity that losing an OPNAV may lessen their accuracy.

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 11:14AM PDT (-0700 GMT)
Reminder: You can see a gallery of pictures of some of the people that you are chatting with at button

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 11:15AM PDT (-0700 GMT)
Hi Phung! Jupiter does have a thin ring as you correctly stated. The source of this ring may be a shattered moon of Jupiter, It is very faint and dark and hard to see compared with Saturn's magnificent ring system. Galileo does have some plans to image the rings during the next year.

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 11:15AM PDT (-0700 GMT)
Thank you Duane. So with Calisto coming up very soon ... any one want to make any predictions of what surprisesare in store for us on this moon?

tayfun: . . . . Wed, Oct 30, 11:15AM PDT (-0700 GMT)
Why is it not possible to use high-gain antenna as an omni-directional antenna? Its transmitter is more powerful.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 11:15AM PDT (-0700 GMT)
Hi Ray, NIMS, at full instrument capability, takes data in 408 different colors or wavelengths over the same observing area. The range is 0.7 to 5.2 microns. Any of these 408 colors can be merged or ratioed to bring out features of interest so it works a bit differently than stereo pairs. Hope this answers your question.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:16AM PDT (-0700 GMT)
LIkelike school: Sara, 4 of Jupiter's moons are big! You can see them at night through binoculars! Other of the small moons might have been captured "rocks" that got too close to Jupiter a long time ago, and now orbit it.

Voyager II, Trois-Rivières, Québec: . . . . Wed, Oct 30, 11:16AM PDT (-0700 GMT)
I'll be back, like Shwarzenneger said! see you later! This is certainly the most interesting chat session on the internet!

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:18AM PDT (-0700 GMT)
More on Ganymede's magnetic field: The suggestion that Ganymede might have it's own magnetic field created some real controversy. Many people think that Ganymede has been geologically inactive for billions of years and isn't likely to have anything going on in the interior that could generate a field. The G2 encounter was an ideal test, because Galileo flew over the north polar region of Ganymede. According to the first encounter results, if Ganymede had an internal field, we would see a particular geometry to the magnetic field at G2. If the field were generated by some other phenomena, this geometry would not be present. The G2 data showed that the magnetic field was oriented such that an internal source is the best explanation. How could that field be created? more in the next message...

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 11:18AM PDT (-0700 GMT)
Anonymous: Your're absolutely correct. There is more to life than just water! There are amino acids (which, by the way, is the main building block of life), hydrogen which is the most prominent atom in our universe as well as in our bodies, helium and other such atoms and molecules that comprise life here on Earth and maybe on other planets

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 11:19AM PDT (-0700 GMT)
Hi Paul.. Mulititudes of hydrated minerals.... We got a peek in G1 and G2 so I suppose I'm not going out on a limb.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 11:19AM PDT (-0700 GMT)
Likelike School: Crystal - you can see pictures of Jupiter from space on our web page. Siengsen - I don't think we really know why Jupiter is the biggest planet in the solar system. There are scientist who develop models of how solar systems are formed. Some of the models do predict large Jupiter size planets. But I unless I'm mistaken (someone can correct me on this), I think how planets are formed is still an open question.

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:20AM PDT (-0700 GMT)
Likelike school: I'm not sure anyone knows the answer to "why is Jupiter so big" but I think I once heard of a theory that Jupiter and the Sun were almost a "binary star system." Many stars that we see in the sky are part of binary systems. This means that there are two stars which orbit each other. If Jupiter was almost a binary star, it just didn't get big enough, and so it didn't start to burn like the sun and instead just became a huge planet. Anyone else know a better answer?

Shadan Ardalan (AACS): . . . . Wed, Oct 30, 11:20AM PDT (-0700 GMT)
*siging off* it's been fun....hope to see you around again (like around 4pm pst)

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:21AM PDT (-0700 GMT)
Duane or Leslie or whomever: There were a few questions about what composes the plume material and the black flows on Io. There is silicate and sulfurous vulcanism - where does each occur?

Dan Erickson - CDS Flt S/W: . . . . Wed, Oct 30, 11:21AM PDT (-0700 GMT)
I have to go now. My computer says I have a meeting. :)

Bontrager Mission Control Santa Cruz: . . . . Wed, Oct 30, 11:21AM PDT (-0700 GMT)
Howdy Steve. When do I get a turn driving this thingy? I want to see if it'll do a wheelie...

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:21AM PDT (-0700 GMT)
Paul Fisher: I don't know if I'd want to make any predictions... But I will anyway :-) I think that Callisto really is a big dead iceball (with lots of craters) and that the tidal forces that probably drive geologic activity on Io, Europa, and Ganymede are so much less that Callisto has no energy source sufficient to create a magnetic field. But I would have guessed the same thing about Ganymede 6 months ago...

Steven Tyler, Systems Engineer: . . . . Wed, Oct 30, 11:22AM PDT (-0700 GMT)
Signing off...back at 4 PM

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 11:22AM PDT (-0700 GMT)
Thanks for coming back Voyager II. We look foward to hearing from you ver soon...

Likelike schoolanonymous: . . . . Wed, Oct 30, 11:26AM PDT (-0700 GMT)
Likelike School, Honolulu ,Chanie-Why is Jupiter red and orange? Sherrie Ann-Does Jupiter have volcanoes? C'mare-Would it be possible to land on Jupiter because it is made of gases? Tiffany-How does Jupiter travel around the sun? Mahalo and Aloha, Thank-you and Good-bye from Honolulu, Hawaii.

Lou D'Amario, Galileo Navigation: . . . . Wed, Oct 30, 11:26AM PDT (-0700 GMT)
Signing off - back this afternoon. Got to go check on where Galileo is.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 11:26AM PDT (-0700 GMT)
Bontrager: I've uuencoded your message and will put it on the command system as soon as I can get approval from the project manager.

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 11:27AM PDT (-0700 GMT)
If there are any people there with memories long enough, one of my former students, Alan, wants to know how long Galileo was in design/construction?

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 11:27AM PDT (-0700 GMT)
Annie at Likelike, yes "nature" is all there is on Jupiter. It's not the same nature that you can see in Foster Gardens. We don't think there's any "solid ground" even way down in the atmosphere. But to me nature just means anything in our world that was not built by people. On Jupiter, there is only one thing I know of that was built by people. That is the Galileo Probe. By now the heat and pressure in Jupiter's atmosphere has not only smashed the Probe, they also have separated the Probe into its individual atoms. These atoms are of magnesium, carbon, aluminum, and others, and there would be no way for a scientist to know that they were once from the earth. So, lots of nature on Jupiter, but I don't think you'd like to trade it for what you have in Hawaii.

James Warren: . . . . Wed, Oct 30, 11:27AM PDT (-0700 GMT)
To Jim Taylor or Tal Brady: In regards to the new ground based array of electronically linked antennas mentioned in the JPL press release of 10-18-96, I was wondering about how much of an increase in the 160bps, if any, would there be?

Likelike schoolanonymous: . . . . Wed, Oct 30, 11:27AM PDT (-0700 GMT)
Likelike School, Honolulu ,Chanie-Why is Jupiter red and orange? Sherrie Ann-Does Jupiter have volcanoes? C'mare-Would it be possible to land on Jupiter because it is made of gases? Tiffany-How does Jupiter travel around the sun? Mahalo and Aloha, Thank-you and Good-bye from Honolulu, Hawaii.

Stuart Stephens, Ultraviolet Spectrometer Team: . . . . Wed, Oct 30, 11:28AM PDT (-0700 GMT)
signing in (busy morning!) ... Gerhard, about your Jupiter aurora question: Very timely, by the way, since we just received our real-time inbound-to-Callisto aurora observation! This was taken with the UVS (Ultraviolet Spectrometer) and EUV (Extreme Ultraviolet Spectrometer) observing simultaneously. The EUV spins with the rotating part of the spacecraft so that it is pointed perpendicular to the Earth-pointing direction, and when it's field-of- view crosses Jupiter we also observe with the UVS pointing at 90 degrees also (UVS can't point closer to the Earth direction because the booms and antenna are in the way). About the aurora.... Pretty much I believe you got it right! Actually, it spans several Earth diameters, so a couple times 10,000 km across! (I'll try to provide a link to some aurora images for you....) Also, I believe it is also there in visible wavelenghts, and I think SSI (the imaging camera) and NIMS (Near-Infrared Mapping Spectrometer) have plans sometime during the mission to observer the aurora also (help me out on this one....). But it's most energetic in the UV (UVS observes between about 1130 and 4320 Angstroms wavelength, and EUV between 540 and 1280 Angstroms. Our eyes can see between about 4000 and 7000 Angstroms).

tayfun: . . . . Wed, Oct 30, 11:28AM PDT (-0700 GMT)
To SSI team: (Correction) If it were possible, would you replace Galileo with a Voyager 2 with a full fuel tank and RTG at maximum power?

Jeffrey Chung, SEQ/CDS: . . . . Wed, Oct 30, 11:29AM PDT (-0700 GMT)
Why Big? One answer to this "why" question is- Jupiter is large enough so that it can absorb much of the interplanetary space-matter (meteorites, comets, etc.) and protect the earth and its inhabitants. We owe quite a lot of our existence to Jupiter's size- recall Shoemaker- Levy comet(s) as it slammed into jupiter back in 7/93 (or 94?).

Tal Brady .. Flight Software: . . . . Wed, Oct 30, 11:29AM PDT (-0700 GMT)
Hi Guys I'm back from my meeting.

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:29AM PDT (-0700 GMT)
Ashwin: Until Galileo (according to Bill Smythe) we didn't know which were which, although there were theories. The ones that SSI saw - shorter wavelentghs - are hotter volcanos and relate to silicate volcanism. These include places like Marduk and Pele. Others that NIMS saw, but SSI did not see would be the cooler sulfur volcanism. Good question....I should know this off the top of my head!

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:30AM PDT (-0700 GMT)
Likelike - if you're still there... Jupiter is colorful because of all the different kinds of material in its atmosphere. We don't know what causes what color yet. Jupiter doesn't have volcanoes, but its moon Io has the only volcanoes ever seen to be erupting besides earth. We couldn't land on Jupiter, but we could 'glide' in and fly around a while! And finally, Jupiter orbits the sun like all the other planets do - the sun continually tugs Jupiter, but Jupiter keeps missing the sun and rotating around it. This little dance goes on and on....

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:30AM PDT (-0700 GMT)
Ashwin, would you like to answer Chanie's question on why Jupiter is red and orange...

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 11:30AM PDT (-0700 GMT)
Likelike school: Hi Sara. I just want to echo Leslie Lowes remarks about Jupiter's moons. They are huge and one of them even has active volcanoes! This moon is named Io and is sometime referred to as the "Pizza" moon. It doesn't pour out lava as we know volcanoes do on Earth. Instead, it has been said that it spews out sulfur and other gasses. It is one of the most interesting moon around Jupiter because it is the only one that we know of that is completely active with volcanoes...

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 11:30AM PDT (-0700 GMT)
One of my students, Tim, would like to know what your majors were in college (and what college you went to ).

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 11:30AM PDT (-0700 GMT)
Likelike school: Rings around planets are icy and rocky materials that are in a region near the planet such that the gravitational forces are stable. Basically, when you have stuff near a planet, there's always a "tug of war" game between the planet's gravity, and the materials resistance to changing its motion. A ring will form when those forces balance each other out.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 11:31AM PDT (-0700 GMT)
Paul, I seem to recall mid-70's. It was approved in 1977.

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:31AM PDT (-0700 GMT)
More on Ganymede's magnetic field: There are several possible sources for a internal mag. field. (1) A self-generating dynamo in an iron core (this is how we think Earth's magnetic field is created). (2) A similar dynamo in a highly saline water layer deep in Ganymede (this is how some scientists think the magnetic fields of Uranus and Neptune are created). (3) Remnant magnetism "frozen in" to rocks inside Ganymede. I think that the last of these is very unlikely because Ganymede's magnetic field is so strong (at least 5 or 6 times as strong at Ganymede's surface as Jupiter's field at the same point). It's very hard to get such large mag. field strengths when Ganymede is mostly made up of non-magnetic material. The group at UCLA working on this data (they have a paper that will come out in the journal Nature very soon -- look for reports in your local newspapers) believes that an iron core is the most likely source.

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:31AM PDT (-0700 GMT)
Ashwin: Correction. Volund, not Pele - I misremembered the map.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 11:32AM PDT (-0700 GMT)
Paul's student: I have a BS and a MS in physics. For my BS, I went to Cal Poly Pomona, a California State university in Southern California. For my MS, I went to Rensselaer Polytechnic Institute, in Troy, NY.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 11:32AM PDT (-0700 GMT)
Chanie asks: Why is Jupiter red and orange? You know that's a *very* good question! No one really knows the answer to that! When you ask the atmospheric scientists they just wave their hands around and mumble something like: "Methane Ammonia hydrocarbon chemistry bla bla" Study your chemistry and perhaps you can figure it out some day!

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 11:32AM PDT (-0700 GMT)
Tiffany in Hawaii, Jupiter travels around the sun in a near-perfect circle. It takes 12 years to go around the sun once (instead of one year, like the Earth). It is moving slower than the Earth, and it is five times further away from the sun as the Earth is. But a very interesting thing is that Jupiter's day (how long it takes to "spin around" its own axis) is less than 10 hours long, instead of 24 hours as for the Earth. Therefore, a Jupiter calendar would have over 10,000 days in it! (or over 350 "months").

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 11:32AM PDT (-0700 GMT)
My major was Geography, and I went to a California State University in Northridge California. I have hopeful plans to someday get my Master's

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:32AM PDT (-0700 GMT)
Paul, I have a bachelor's degree in Physics from U. Texas at Arlington, and a Master's in Applied Math from Cal State LA.

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 11:32AM PDT (-0700 GMT)
Paul Fisher - Galileo was in design (and re-design!) and construction (re-construction!) from about 1978 through 1989 when it was launched. The original mission was supposed to launch in 1982, but was delayed by NASA's changing their minds about which launch vehicle. The redesigned Galileo was going to launch in 1986 on the Space Shuttle, but the Challenger blew up -- as we all sadly remember -- just a few months before the scheduled Galileo launch. NASA put all the Shuttle programs on hold until the Shuttles were themselves redesigned to reduce the risk of another tragedy. By 1989, the Galileo Orbiter had another low-gain antenna on its backside, so that we could communicate during the part of the trajectory that took us inbound toward Venus, as well as during the close flyby of the Earth that took place after Venus. In all, we flew the spacecraft past three planets and two asteroids before we even got to Jupiter. No wonder some of us think we've spent the better part of our lives on this one project.

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:33AM PDT (-0700 GMT)
Paul F. and students: I think Galileo began officially in 1979 and was launched in 1989! I majored in Math and got a minor in Physics. I went to the University of Arizona in Tucson.

Tal Brady .. Flight Software: . . . . Wed, Oct 30, 11:33AM PDT (-0700 GMT)
James, No increase from 160 bps, but more times when we can use higher rates. Now we spend a lot of time between 32 and 80 bps.

Bontrager Mission Control Santa Cruz: . . . . Wed, Oct 30, 11:34AM PDT (-0700 GMT)
I'm outta here Steve. The whole Board of Directors is banging on the door. Thanks for the invite. I'll check back later if I can. KB

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:35AM PDT (-0700 GMT)
Interesting question about replacing Galieo with Voyager. Hmm. While the thought of all that bandwith leaves the SSI team salivating, I think the answer may be suprisingly 'no'. Because the SSI is a CCD camera (like todays digital video cameras) and not a TV camera like voyager, we have much more sensitivity do detect thin hazes on Jupiter and aurorae on Io, for example. Also, we have new filters that let us see different levels in Jupiter's atmosphere and minerals on the satellites. This is totally new from Voyager.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:35AM PDT (-0700 GMT)
Duane, will we be getting close enough to Callisto next week to get the type of info you guys will need to determine if there is a magnetic field there?

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 11:35AM PDT (-0700 GMT)
Paul's student: BA's in Physics and Theatre Arts from Univ Calif at Santa Cruz

Jeffrey Chung, Galileo SEQ/CDS: . . . . Wed, Oct 30, 11:35AM PDT (-0700 GMT)
NJ school: I got a Bachelor's degree in Electrical Engineering ("you can't have gEEk without the 'ee'"...) from cornell back in '92; however, there have supposedly been german, art, & english majors on the Sequence team & ~400-member flight team in general.

Jim Erickson, Science & Sequence Office: . . . . Wed, Oct 30, 11:36AM PDT (-0700 GMT)
Paul Fisher - When I started with Galileo in 1979, it was in full development. Approval from Congress for a project start had been in 1977, with preliminary work for a few years earlier. My major was in Physics for my B.S., and Program Management/Finance for my MBA.

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 11:36AM PDT (-0700 GMT)
Bontrager: Thanks for dropping in. Let's do lunch...

w.teschner: . . . . Wed, Oct 30, 11:36AM PDT (-0700 GMT)
Hello, Flight Team, is it possible to get the flight parameters of galileo (Jovicentered) for the actual and coming time?

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 11:36AM PDT (-0700 GMT)
Likelike school: C'mare, to answer your question, Jupiter has no land mass to land on. It is a huge "ball of gas." This doesn't mean that any spacecraft would go right "through" it, this just means we're able that a spacecraft or probe would descend into its atmosphere and eventually burn up or become crushed by the pressures of Jupiter

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 11:36AM PDT (-0700 GMT)
Paul's student--I have B.S. and M.S. degrees in aerospace engineering from MIT.

Tal Brady .. Flight Software: . . . . Wed, Oct 30, 11:37AM PDT (-0700 GMT)
1. GLL studies began in 1976 I think. 2. I attended UCI majoring in Philosophy

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 11:37AM PDT (-0700 GMT)
Leslie Tamppari: You didn't tell Paul's student that you are getting your PhD!

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 11:37AM PDT (-0700 GMT)
James Warren - The answer to your question about the 160 bits per second is: that's the highest data rate built into the flight software of the spacecraft. Planning for that data rate already took into account the fact that we were also planning and building the array capability. The array is operational as of this week! We had been testing it for a couple of months before that. One of the tests was to have the spacecraft transmit 160 bits per second for the first time. No single station could receive data at that rate, not even the largest (70-meter diameter) station in Australia. But the array worked just as it had been planned, and we received 160 bps at just the strength we expected. We in telecom felt good about that. I'm sure the folks on the Galileo "S-band task" that built the software and the hardware that make the array possible, also felt good. On second thought, they probably just felt tired because they had been doing these tests almost daily, just about every night.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 11:38AM PDT (-0700 GMT)
Stuart, NIMS is observing aurora in C3 along with UVS and Fields and Particles. Should be an interesting data set.

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:39AM PDT (-0700 GMT)
To Aswin, re Io plumes and flows. The plumes of Io are composed of very small particles made up of the same things Io is made up of -- a lot of sulfur and oxygen, and probably some silicon, carbon, iron, magnesium...Basically, the volcanoes are sending up plumes of gases that contain very small rock fragments. The dark flows seen on the surface have generally been thought to be made up of sulfur. Theres more and more suggestion that some flows on Io are silicate (rocks like we have here on Earth), but there has not yet been proof positive of any.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 11:39AM PDT (-0700 GMT)
Paul's student: I majored in Physics (BA '66) and Astronomy (MA '67) at the Univ. of California at Berkeley. I did some PhD course work in Celestial Mechanics but decided that I couldn't let them land on the moon without me, so I went to Houston and worked on the Apollo Project in 1968. I've been on Galileo since 1977 (before it had a name) designing satellite tours and interplanetary trajectories the whole time. (It's almost like getting paid to play video games!)

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 11:39AM PDT (-0700 GMT)
Okay folks, here is a question you will enjoy answering: how many hours of sleep do you get a night, from P.J.

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 11:39AM PDT (-0700 GMT)
Must close for now--there is an interesting talk on the Cassini mission to Saturn (learn more at this button It's been real fun, folks!

Katharina, Vienna, Austria: . . . . Wed, Oct 30, 11:40AM PDT (-0700 GMT)
I would like to ask, what sort of radiation there is near Jupiter (just electrons and atomic nuclei, or also electromagnetic like x-ray and gamma)? And what is the source of the radiation ? Are they interplanetary particles (from the solar wind ?) that get trapped and accelerated in the magnetic field lines, or do they origin from Io, or somewhere else ?

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:41AM PDT (-0700 GMT)
Paul Fisher: I have a B.S. in Physics, and M.Sc. and Ph.D. in geology. I went to Washington Univ. (St. Louis) for undergrad and to Brown for grad school.

Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 11:41AM PDT (-0700 GMT)
Oops, let's try that again. The Cassini mission is at this button And I get around 6 hours sleep/nite during the week and try to catch up on Saturdays. Ciao!

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:42AM PDT (-0700 GMT)
Leo and Paul F.'s students: You are correct. I did not mention my current studies. I am currently attending UCLA working on a PhD in Planetary Science. Consequently, I don't get as much sleep as I'd like! About 6-7 hours a night, but I'd sure like more....

Dan Erickson, CDS Flt S/W: . . . . Wed, Oct 30, 11:43AM PDT (-0700 GMT)
I'm back - meeting canceled. I majored in math M.S. from Stanford, B.S. and PhD from Caltech

Jan Ludwinski, Mission Planning Office: . . . . Wed, Oct 30, 11:43AM PDT (-0700 GMT)
For Paul's student: I have a BS in Atrophysics from Michigan State University, East Lansing, Michigan.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 11:44AM PDT (-0700 GMT)
w.teschner: There are trajectory data (orbital elements, etc.) on the Galileo web page at button

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 11:44AM PDT (-0700 GMT)
Paul Fisher - in my case, I get around 7 hours a night. Galileo has nothing to do with it; that's just how much I happen to need. Of course, Galileo has a lot to do with the fact I don't see much TV, I read the morning newspaper last thing at night, and I conduct weekly recognition sessions with my family members (just kidding on that last). I agree with another message I saw above that paying me to work on something I like so much is amost just gravy. Should any JPL management types be looking in, let me say my financial officer definitely doesn't agree with that last statement. 8-)

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 11:44AM PDT (-0700 GMT)
P.J. in New Jersey - I probably get more sleep than most. Itend to try to do all of my work during the week so that I have the weekends free to garden or do chores. In order to do that however, I work 9 to 10 hours a day, and bring home work.

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:44AM PDT (-0700 GMT)
Leslie, re Callisto mag field: We will get close enough to measure a strong Callisto field, but it could also have a field that is too weak for Galileo to detect. If we don't see evidence of a field, we'll at least be able to place an upper limit on how strong the field could possibly be. For reference, we're going to be about 4 times as far from Callisto at closest approach than we were to Ganymede at G2.

anonymous: . . . . Wed, Oct 30, 11:45AM PDT (-0700 GMT)
Enjoyed your Chat Session. I learned alot and learned how little I know. This is a wonderful educational tool and Thank you for making this available.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 11:45AM PDT (-0700 GMT)
Hi Paul and P.J. recently (in preparing for C3) I have had two all-night work sessions meaning no sleep and lots of caffeine. Usually it's 5 hours a night maybe less.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 11:45AM PDT (-0700 GMT)
Paul's student, P.J.: Sleep?.....what's that? Actually, my schedule isn't too bad. During my busy days, I've worked 18-19 hours a day. This is usually when there's some dealine to meet. Most of the time, I get enough sleep. I know that there are others who have a more demanding schedule.

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:46AM PDT (-0700 GMT)
Can someone address Katharina's question regarding the why and how of Jupiter's intense radiation environment?

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:47AM PDT (-0700 GMT)
P.J. in Jersey: I probably average 6-7 hours a night during the week. I try to make up for it on weekends, because I function better the closer to 8 hours of sleep I get.

Dennis Byrnes, Navigation Team: . . . . Wed, Oct 30, 11:47AM PDT (-0700 GMT)
Gotta go now, back this afternoon.

Jeffrey Chung, Galileo SEQ/CDS: . . . . Wed, Oct 30, 11:47AM PDT (-0700 GMT)
Sleep ("PJ" in NJ): I still keep college hours- averaging about 4-6 hours of sleep a night, plus 30-90 minute nap in the evening (bad habit).

anonymous: . . . . Wed, Oct 30, 11:47AM PDT (-0700 GMT)
Gerhard: Here's the location of some Hubble Space Telescope images of the Jupiter aurora: button (The Ultraviolet Spectrometer Team has been working with HST and ground-based observers to coordinate their measurements with aurora observations from Galileo.)

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:47AM PDT (-0700 GMT)
I vote for Duane attempting to answer Katharina's question - and tell her about the dust too!

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:49AM PDT (-0700 GMT)
to Katharina in Vienna: you might want to scroll back a ways. I think an answer I gave to another question would tell you what you want to to know. If not, ask again.

Laura Barnard SPOT & Outreach: . . . . Wed, Oct 30, 11:49AM PDT (-0700 GMT)
The chat session will be coming to a close soon, and I wanted to take the time to thank all of the Galileo volunteers that helped out this morning. I would also like to thank all of the chatters that came to our site and chatted with us! We will have an evening session from 4 to 7PM PST later today if you would like to visit again.

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 11:49AM PDT (-0700 GMT)
Who's anonymous? Can you type in your handle...sounds like a UVS/EUV guy.

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:49AM PDT (-0700 GMT)
The last time I heard from Duane he was doing Venus Geophysics and I was doing Mercury thermal modeling. Isn't planetary Science wonderful?

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:51AM PDT (-0700 GMT)
Re dust and radiation: ok, ok. Here's what I said before: For Paul Fisher: Jupiter has a very strong magnetic field. Such a field is capable of trapping very fast-moving (i.e., high-energy) ions and electrons. These particles emit radiation as they move through various parts of the magnetic field, or, in many cases, can cause radiation damage to anything that they might encounter themselves. In addition, the Jupiter system has at least two sources of small particles (which are broken up and ionized to make these ions and electrons). The two sources are the volcanos of Io and Jupiter's ring system.

Flips: . . . . Wed, Oct 30, 11:51AM PDT (-0700 GMT)
what is the atmosphere on io like?

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:51AM PDT (-0700 GMT)
Well, I have to go get lunch before my noon meeting. Thanks to all the chatters. Let's do it again sometime!

Tal Brady .. Flight software: . . . . Wed, Oct 30, 11:52AM PDT (-0700 GMT)
PJ about 7 unless thre's a problem then sometimes none

Rocketgirl: . . . . Wed, Oct 30, 11:53AM PDT (-0700 GMT)
Is it true that the 4.25 micron feature on Ganymede was also seen on Callisto ? This is important .

Leslie Tamppari-Photopolarimeter/Radiometer Science Team: . . . . Wed, Oct 30, 11:53AM PDT (-0700 GMT)
One more for Flips: THe atmosphere on Io probably stinks. It's probably a lot of Sulfer and other molecules with sulfer in them. It's very thin and variable since it's mostly created by the active volcanism. There is probably also some sulfer dioxide which condenses out on the surface.

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:54AM PDT (-0700 GMT)
I'm not expert, but I'll take a quick stab at Flips' question. Io has a VERY thin atmosphere, caused by SO2 frost evaporating on the sunlit side. The SO2 molecules bounce around the planet until they end up in the dark, cold, night side where they once again freeze out. It is believed that Io's 'atmosphere' may be patchy, located over frost deposits that are sunlit.

Duane Bindschadler, Magnetometer/Dust Detector Team: . . . . Wed, Oct 30, 11:54AM PDT (-0700 GMT)
Sorry, gotta run. Thanks to all you folks who asked questions, and to all those who just "listened" -- I hope you find this even half as interesting as we do!

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 11:54AM PDT (-0700 GMT)
Re radiation for Katharina: Don't forget that those ions and electrons carry carry energy and can penetrate through matter, which is also radiation.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 11:55AM PDT (-0700 GMT)
Paul's students: I get 7 hours or so most nights, but its not enough because making sure we get the word out about Galileo takes ALOT of energy! I eat more than I used to and don't put on weight. I think a big challenge that alot of us face is to make time to have a life outside of work. We've got alot of interests outside of work (NO NERDS here!) I like skiing, paragliding, mountain bike riding, camping, and singing!

Ashwin Vasavada, SSI Atmos. Sci.: . . . . Wed, Oct 30, 11:55AM PDT (-0700 GMT)
I'll second Leslie's remarks about vulcanism - I left that part out.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 11:57AM PDT (-0700 GMT)
To Rocketgirl, Yes... Affirmative. The 4.25 micron feature seen on Ganymede was seen on Callisto first.

Tal Brady .. Flight software: . . . . Wed, Oct 30, 11:57AM PDT (-0700 GMT)
Well looks like we're ending soon .. Nice chatting with you. Likelike kids if still there glad you could come. You guys are the ones who might fly to Mars or even Jupiter someday. Keep on learning.

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 11:57AM PDT (-0700 GMT)
Paul's students: I got a B.S. in math with an Astronomy minor from San Diego State Univ.

Dan Erickson, CDS Flt S/W: . . . . Wed, Oct 30, 11:58AM PDT (-0700 GMT)
Speak for yourself, Leslie. I'm proud of being a nerd ;-)

Rocketgirl: . . . . Wed, Oct 30, 11:58AM PDT (-0700 GMT)
Thank you. Now is the 4.25 feature seen on Europa ?? ..

Stuart Stephens, Ultraviolet Spectrometer Team: . . . . Wed, Oct 30, 11:58AM PDT (-0700 GMT)
Hi Leo (and Gerhard....)! Yes it was a UVS/EUV guy who provided the HST aurora button at 11:47 am PDT. I should mention, too, that we're getting our C3-inbound aurora spectra from UVS and EUV in the middle of our Io torus observations with the same instruments. Because they're both pointed at 90 degrees from the spacecraft Earth-pointing direction, we sweep our instruments' field-of-view across the midnight side of the torus (side away from the sun), then across Jupiter for the aurora, then across the noon side of the aurora (side nearer the sun). If you imagine a torus (donut!) surrounding Jupiter in the vicinity of Io's orbit (about 3 Jupiter diameters from the planet), you can see that as we come in on the current trajectory, we take about 5 days to cover this region (well, actually out to Europa's orbit, about 4-5 Jupiter diameters from the planet).

Steve Collins Galileo Backroom (AACS): . . . . Wed, Oct 30, 11:59AM PDT (-0700 GMT)
Marcia: What's giving a line at 4.25 nm?

who: . . . . Wed, Oct 30, 11:59AM PDT (-0700 GMT)
Leslie, there are alot of nerds in Galileo. Don't kid yourself. They need to get a life.. (you probably have one but some don't..)

Stuart Stephens, Ultraviolet Spectrometer Team: . . . . Wed, Oct 30, 11:59AM PDT (-0700 GMT)
correction: "noon side of the TORUS...." Bye, thanks for joining in!

Paul Fisher - Morristown, NJ: . . . . Wed, Oct 30, 12:00AM PDT (-0700 GMT)
Phil would like to know how long it takes to get a picture back from Galileo (shutter time to showing up on the Web)

Katharina and Gerhard, Vienna, Austria: . . . . Wed, Oct 30, 12:00AM PDT (-0700 GMT)
Many thanks for all those interesting answers. Duane, thanks for the radiation answer, and "anonymous": thanks for the link to Hubble. Greetings to all those great people who make this dream of a Jupiter orbiting mission come true. Just as it has been said somewhere (Dan Goldin ?): This team never gave up... and now despite all the problems that might happen on such a pioneering mission we now have reached our goal - a satellite in Jupiter orbit !! So thank you all, and see you again on the next web chat ! (P.S. Please do again a morning chat on the next chat, because from Europe the "evening chat" is very very deep at night in Europe.) Bye...

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 12:01AM PDT (-0700 GMT)
Well, I just about outta here. I hope to sit in part of tonight's session as well. You should see me with alt-tab on my computer, going back and forth between the chat, my e-mail, my word processor. I'm one of those guys who was a nerd or a geek long before those terms were even used. We were just socially challenged in those days. (I'm an EE from Stanford in '61, MS in '62, then immediately went into communications systems engineering for spacecraft with the old RCA right out of college. Back in those days, there was no such thing as communications systems engineering either, at least not by that name. So I've had a great life learning new things. Hope to see some of you this evening. Jim T.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 12:01AM PDT (-0700 GMT)
To Rocketgirl... There is minimal data for Europa as yet so it wouldn't be accurate to say. Ask again after C3 data return or keep listening/viewing the Galileo website.

Rebecca Westbrook, Outreach: . . . . Wed, Oct 30, 12:01AM PDT (-0700 GMT)
Well, folks, it's about time to bring this chat session to a close... I'll let it stay for another 5 minutes or so, but if you still have questions after that, please join us for the afternoon session at 4:00pm PST. Thanks!

wolfgang teschner, germany: . . . . Wed, Oct 30, 12:02AM PDT (-0700 GMT)
to Navigation (!): Is it possible to post the trajectories of the probe for all the next say 2 weeks? jovi-centered, of course... I own a sw which could read this and display it and even compute a trajectoery< of its own (not too exact, that is).

Leo Cheng, SEQ Integrator: . . . . Wed, Oct 30, 12:02AM PDT (-0700 GMT)
Thanks everyone. I'll be back later.

tayfun: . . . . Wed, Oct 30, 12:02AM PDT (-0700 GMT)
Which side of Io will be imaged on C3?

Dan Erickson, CDS Flt S/W: . . . . Wed, Oct 30, 12:02AM PDT (-0700 GMT)
Must go. Need fuel. Carbon-based sustenance. Thanks to all the chatters for your interest and your questions.

Jim T (spacecraft and ground radio): . . . . Wed, Oct 30, 12:03AM PDT (-0700 GMT)
Laura, in case you hadn't noticed, the time tags on these messages are now saying 12:XX am pdt. Maybe by this evening, you can get your computer wiz to update us to standard time, in the pm. Regards, Jim T.

Leslie Lowes, Galileo Outreach: . . . . Wed, Oct 30, 12:05AM PDT (-0700 GMT)
Wolfgang: the Galileo web page has this information. Please see the address: button

Paul Herrera, Near Infrared Mapping Sepctrometer (NIMS) Team: . . . . Wed, Oct 30, 12:05AM PDT (-0700 GMT)
Must go now. Hope I helped answering some of your questions. Thanks again. Maybe I'll be back at 4..

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 12:06AM PDT (-0700 GMT)
Steve, the 4.25 micron region of the spectrum provides information about surface composition other than "ice". It could be hydrated minerals of which many have this same characteristic. More info as research continues.

Tal Brady: . . . . Wed, Oct 30, 12:06AM PDT (-0700 GMT)
Phil, it depends on how long the encounter period is. Images are recorded at the time of shuttering (within 1 minute). Then they are played back during the cruise period after the encounter period. Encounters are usually about a week. Cruise periods are 1 to 2 months. When the playback gets to the image the it takes about 10 minutes to get it off the recorder and compress it.. Then it goes into the buffer for downlink and downlink of the image varies between about 40 bps and 160 bps several times a day. On average it can take a little less than 1 hour up to about 6 hours for the image to reach us on earth. Hope that helps.

Marcia Segura, Near Infrared Mapping Spectrometer Team: . . . . Wed, Oct 30, 12:07AM PDT (-0700 GMT)
Signing off til 4pm