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2008 Nov 19 A year of astronomy. The search for life beyond Earth. From The World in 2009 print edition. By Alun Anderson. Excerpt:
No discovery in science could be more dramatic than finding life elsewhere in the universe. ...That discovery can’t be promised for 2009 but we will see a giant leap in our capability to find Earth-like planets that could provide good homes for life. In April NASA will launch Kepler, a powerful space telescope that can monitor simultaneously 100,000 stars and look for the faint signal that reveals an orbiting planet.
The choice of the name Kepler is timely, for 2009 is the 400th anniversary of two of the most momentous events in astronomy. Both are to be celebrated in the International Year of Astronomy, a global festival designed to “help the citizens of the world rediscover their place in the Universe”. The first of those events was the publication by Johannes Kepler, a mathematician living in Prague, of Astronomia Nova, .... The second was the first use of an astronomical telescope by Galileo Galilei.
...The Kepler telescope will be launched amid a flurry of discoveries of planets circling distant stars. Since the first “exoplanet” was found in 1995 by Michel Mayor at the Geneva Observatory, more than 300 have been charted. Europe’s COROT space telescope has been particularly successful and will find many more planets in 2009. These discoveries have been of large fast-orbiting planets which are so close to their suns that they are far too hot to support life of any kind.
...The Kepler telescope will hang in orbit and stare continuously at a field of 100,000 stars in the Cygnus-Lyra region of the Milky Way. Kepler will watch them all for three-and-a-half years
...“If Kepler is successful it will be NASA’s most boring operation,” says David Koch, an astronomer at NASA Ames Research Centre, which runs the Kepler project. “But the results will be sensational.” Kepler’s scientists estimate that the telescope should find at least 50 Earth-sized planets in one-year orbits, plus many bigger planets. They even expect to find quite a few planets orbiting pairs of stars. “A pirouette of two stars and a planet can be stable,” explains Dr Koch. “The planet may orbit one of the pair of suns if it is in close enough, or both suns.” Living on such a planet might be a little strange, with multiple sunrises and sunsets.
If all goes well Kepler will leave us with a catalogue of planets that could support life. That will help plan future missions....
2008 November. The stars her destination, by Roberta Kwok, Photo by Marcus Hanschen
A business major's epiphany leads her to become a NASA scientist.
Excerpt: Natalie Batalha's worst enemy is the clock. Installed around the corner from her office at NASA Ames Research Center, a looming LED display is counting the days, hours, minutes and seconds until the launch of the Kepler Mission: NASA's first attempt to find habitable Earth-like planets in our galaxy. ...When the clock runs down to zero next spring, Batalha will stand with her family at Cape Canaveral in Florida to watch Kepler's take-off. The spacecraft's telescope will peer at one slice of the sky for three-and-a-half years, to look for signs of terrestrial planets using a technique called the transit method. Batalha likens the process to a fly passing in front of a car's headlight: Every time a planet passes in front of the star it orbits, it dims the star's light a little, the same way a fly would dim a headlight as it flew past. As part of preparation for launch, Batalha has been choosing—very, very carefully—the 170,000 stars that Kepler will observe from among the 13 million in its field of view. ... "Can you imagine that within your lifetime, you will probably be able to look up in the sky and say, 'That star right there has a habitable Earth-like planet orbiting it'?" asks Batalha, an associate professor at San Jose State University. "That's astounding. It's going to change the way people understand their place in the universe."
... working in the lab of Gibor Basri, an astronomer at Berkeley... She recalls one day, while they were sitting at a computer looking at observations of young stars, or "baby Suns," from a new instrument at Lick Observatory, when Basri turned to her and said, "Natalie, no one else in the world has data like this." The thrill of discovery, she says, clinched her decision to be a scientist. "It must be, on a much smaller scale, like the feeling Galileo had when he saw Jupiter's moons," she says. "That's the gateway drug."
... One of her early contributions to the project was convincing the science team to move the telescope away from the plane of the Milky Way, where bright giant stars would obscure the fainter, Sun-like stars they wanted to see. ..."Natalie was one of the few people to realize that the original target region chosen for the Kepler Mission was a mistake," says David Latham, a mission co-investigator and senior astronomer at the Smithsonian Astrophysical Observatory....
2008 Oct 10. How Long Until We Find a Second Earth? by Robert Kunzig, Discover Magazine Nov 2008 issue. Excerpt: [Photo: The 55-inch mirror on the Kepler space telescope will focus starlight on its detectors. ...Kepler will seek slight variations in a star's brightness, a signal that a planet is crossing in front of it.]
Gliese 876 is a modest star, just one-third the mass of our sun and only 15 light-years away, but it has a history-making planetary system all its own. In 1998 a team led by Geoff Marcy of the University of California at Berkeley detected the first sign of something interesting there: a giant planet, twice the mass of Jupiter, circling Gliese 876 once every two months, its gravity yanking the star back and forth at the speed of a jet plane. ...In the past decade, announcements of Jupiter-size planets have become commonplace.... In 2005, however, with the help of improved detection software, Marcy’s team turned up something else orbiting Gliese 876—something truly new. ... It was another planet, orbiting in just two days... dubbed Gliese 876 d, is clearly no Jupiter, Marcy realized. It is no more than seven or eight times as massive as our own: a “super-Earth.” ...Gliese’s super-Earth lies so close to its star that it has just about no chance of being inhabited. If it has an atmosphere at all, it probably consists of dense steam, says Greg Laughlin of the University of California at Santa Cruz, a member of the discovery team. ... the Swiss astronomers who in 1995 discovered the first Jupiter-like exoplanet...said in June that they had identified not one but three super-Earths orbiting a single star 40 light-years away. The smallest is just four times as massive as Earth. “We’ll find an Earth-mass planet by 2010,” Laughlin predicts, “and an Earth-mass planet that’s potentially habitable by 2012.”
...A French satellite called Corot, the first space telescope devoted primarily to looking for rocky planets, is in orbit now. An even more capable American mission, Kepler, ... is expected to find hundreds of Earths, including the first ones orbiting stars like the sun at distances like that of our own Earth. Then, in 2013, NASA will launch a giant infrared telescope called the James Webb Space Telescope ... just might be able to provide the first indication of life—a telltale molecule, such as oxygen, in the planet’s atmosphere—on a super-Earth circling another star. By 2014 headlines could be announcing the first tentative evidence of life beyond our solar system.
... an astrophysicist named William Borucki at NASA’s Ames Research Center in Mountain View, California. In 1984 Borucki published his first description of the transit technique .... Borucki well remembers the effect he had with that 1984 paper, published in the journal Icarus. “There was no effect,” he says. “It was pretty much ignored.” At that time most researchers thought the way to look for other planets was through astrometry. Borucki was convinced that looking for planetary transits through photometry would be simpler and cheaper. Measuring the brightness of a star over time, he reasoned, would require a much smaller space telescope than trying to take a picture sharp enough to resolve a planet or a tiny loop in the star’s trajectory.
Borucki’s peers were skeptical, though—first, that a transit of an Earth would even be distinguishable against the background noise of the star’s fluctuating light, and second, that it was possible to monitor 5,000 sunlike stars at once, as he proposed to do. ...Borucki’s initial idea for a detector still raised eyebrows. He wanted to drill 5,000 holes, one for each star, into a metal template and put it near the focal plane of the telescope, with an individual photodiode and integrated circuit behind each hole. “People in the industry refused to even talk to us about that design,” recalls David Koch, the deputy principal investigator, whom Borucki roped in to his quest in 1992. Borucki’s basic concept was rescued by the emergence of the charge-coupled device, or CCD—the light-sensing chip that was then new and is now in hundreds of millions of digital cameras. A CCD can record the brightness of many stars at once, thus eliminating the need for thousands of photodiodes.
Borucki and Koch first proposed their mission to NASA in 1994 ...again in 1996, 1998, and 2000. “Each time they came back with a list of reasons why we weren’t selected,” Koch says. “It won’t work because of this, it won’t work because of that, they said. And we went back and worked on it until we eliminated every reason they couldn’t select us.” ...In 2001 NASA finally approved the mission. ... Because it has CCDs, Kepler will be able to monitor 100,000 stars simultaneously. It will spot variations as small as 10 parts per million in their light output.
...In the fall of 2007 David Charbonneau of Harvard began deploying a network of small telescopes in Arizona that will be focused on detecting transiting super-Earths in the habitable zones of red dwarf stars. ...In 2001, using Hubble, Charbonneau and his colleagues detected the first exoplanetary atmosphere
... Kepler will follow a 53-week orbit around the sun, meaning that it will steadily drift farther behind Earth. “It loses a week a year,” Borucki says. “So 53 years after launch, it will come back to Earth. At that point, I expect, people will go up and pick up the spacecraft and put it in the Smithsonian. I
know that sounds far-fetched. But I really think it will happen.”
2008 Sep 18. How Rare is Earth? by Edna DeVore, Space.com. Excerpt: Is the Earth a rare place in our galaxy, or are Earth-like planets as common as stars? Scientists do not yet have the data to answer this question, but should get it through NASA's upcoming Kepler Mission. With this space mission, we're taking a big step on the quest to understand our place in the universe. The Kepler Mission has the sensitivity and precision to discover small planets, and determine whether they are in the habitable zone. The results will help answer the question: "Are Earth-like planets rare, or common?"
That's a great question. For me it's a wonderful adventure to be a part of this mission. What about you? What's your opinion? If you are an educator, what do your students think about the search for other Earths? Join us, and send your name and opinion into space.
2008 June 19. Closing in on Extrasolar Earth. By Edna DeVore, SETI Institute - space.com - Excerpt: ...Almost weekly, there's an announcement of yet another extrasolar planet around a neighborhood star. This week, it's a triple system of super-Earths discovered at the European Southern Observatory at La Silla using the HARPS (High Accuracy Radial velocity Planet Searcher) instrument....
2008 June 9. How to Find Faraway Moons. By David Powell - Special to SPACE.com. Excerpt: While the number of confirmed extrasolar planets is now approaching 300, the tally of extrasolar moons so far identified is still a rather disappointing zero. ...But the search is not impossible, says Darren Williams, associate professor of physics and astronomy at Penn State Erie, the Behrend College. Williams believes a moon in orbit around a known extrasolar planet will also be detectable if we look hard enough with the right techniques.
...
Finding moons is more than just an academic quest to count them up. Planetary satellites can be highly interesting in their own right. It's possible, for example, that life could exist on extrasolar moons, researchers say. And it has been suggested that the ocean tides induced by Earth's moon may have been necessary to create the conditions for life on our planet to begin. At the least, the evolution of life has been affected by our moon's constant tugging.
...It will be easier to see moons that happen to transit the face of a star, such as what the space telescope Kepler will attempt to do starting next year," Williams explained. The space-based Kepler observatory will note dips in starlight caused by planets crossing in front of stars. If the planets are aligned in such a favourable manner, then thinking goes, moons ought to transit the stars too. ...A similar conclusion is reached by Szabó, Szatmáry, Diveki and Simon in a paper published in Astronomy and Astrophysics in 2005. They conclude that the Kepler mission should identify a few extrasolar moons using this method of detection.
2008 May 14. U.S. plans year of space missions. BY ROBERT S. BOYD • MCCLATCHY NEWSPAPERS - freep.com. Mars landing is first in the lineup....
2008 May 9. Elvis, bin Laden and Hitler Join Mission to Mars. by Nell Greenfieldboyce, All Things Considered, National Public Radio (NPR). Excerpt: When the Phoenix lander touches down on Mars later this month, so will the names of thousands of people... Elvis Presley, Donald Duck, John Lennon and Adolf Hitler are all onboard the Phoenix lander. Courtesy of the Planetary Society. ...If names are tricky, what about essays? NASA is soliciting 500-word messages that will rocket into space next year onboard the Kepler spacecraft, which will search for Earth-like planets. David Koch, who works on the project at NASA's Ames Research Center, says he hopes millions of people will sign up. "If somebody wants to submit Mickey Mouse as a name, that's fine with me," he says. And if someone wants to write something offensive, even something racist and nasty, "if that's what they want to do, I'll let them." He says that doesn't mean NASA endorses those views. Koch just doesn't like restrictions, because "the whole idea is to let people show their enthusiasm for the space program," he says. "If somebody wants to be a downer, I'll let them be a downer. People do have those instincts sometimes."....[audio online]
Other articles on the Name in Space:
2008 May 8. Throngs rove through JPL. Mary O'Keefe, La Cañada Valley Sun. Excerpt: Close to 30,000 visitors got a up close and personal view of space exploration during Jet Propulsion Laboratory’s annual open house on May 3 and 4.
...One popular area was the search for Earth-like planets. A demonstration of the “wobble” effect was made simple with markers, a globe and a weight. A marker was placed on the bottom of a globe that represented a star, as it turned the inked circle remained small. Then a weight was added to the side of the globe representing the gravitational pull of a planet. With this added the pen drew a bigger, “wobbly” circle. This wobble effect helps scientists find smaller planets near large stars.
...
The display area also included information on Kepler, the first space mission to search for habitable Earth-size and smaller planets. With a planned launch in 2009, the spacecraft will continuously monitor over 100,000 stars similar to the Sun measuring the light variations. When a planet passes in front of its parent star, like when the Earth moves in front of the Sun, it is known as a transit. Kepler will search for transits of distant “Earths.”
2008 May 5. Another (Better) Opportunity to Send Your Name to Space
Written by Nancy Atkinson, Universe Today. Excerpt: ...Earlier today, Ian reported on how the Lunar Reconnaissance Orbiter mission is offering the chance for the public to 'ride along' to the moon by sending their names to be added to a computer chip which will be embedded on the spacecraft. Well, not to be outdone, the upcoming Kepler mission that will search for Earth-sized exoplanets is offering the same chance. But this is no sluff opportunity where you just fill in your name and you're done: you've got to work a little and be creative! The Kepler folks would like you to also state in 100 words or less why you think the Kepler mission is important. I think that's a great idea, and I'm going to add my name and statement right away. But there's more reasons why I prefer the Kepler mission's approach to sending your name to space:
- Your name will be in an exciting Earth-trailing heliocentric orbit, going around the sun every 372.5 days.
- This activity is done in association with the International Year of Astronomy 2009.
- Your name will be on the spacecraft that will likely identify the first Earth-sized or smaller planet orbiting another star.
- Your name will be launched on board a Delta II rocket.
- Your name will be part of the mission that will determine the frequency of terrestrial and larger planets in or near the habitable zone of a wide variety of spectral types of stars.
...So, here's where you can add your name....
2008 Mar 24. Searching for Earth. By Henry Bortman. Astrobiology Magazine. Excerpt: More than 250 planets have been found orbiting distant stars. Most of them are “hot Jupiters,” giant planets orbiting close to their stars, unlikely places for life to take hold. NASA’s Kepler mission hopes to find habitable planets like Earth. Or, perhaps, to discover that there aren’t many of them around to find. ...NASA’s Kepler spacecraft will search for Earth-size planets around more than 100,000 stars. ...It is “NASA’s first mission capable of detecting Earth-size and smaller planets around other stars,” says David Koch, an astrophysicist at NASA Ames Research Center near Mountain View, Calif., and the Deputy PI on the Kepler project. Koch and his colleagues have successfully completed a critical test of the telescope’s imaging system, using hardware identical to what will be used on the spacecraft.
...
The dimming caused by a transit is miniscule: one-hundredth of one percent for an Earth-size world. For comparison, imagine you’re inside looking out through a window. If you open the window and look directly out, the change in light intensity is about one percent. Kepler’s detectors will find Earth-like planets by measuring changes more than one hundred times as small.
...
Koch says, “if you were to get back away from our solar system and look at the Earth transiting our sun, and it went right across the center of the disk of our sun, that would take 13 hours.” By noting the timing of a sequence of a planet’s transits and knowing the mass of the star that the planet orbits, the Kepler team will be able to calculate the planet’s distance from the star. How much a star’s light dims during a transit will indicate how large the planet is. Larger planets block more starlight.
...
Kepler’s designers expect to detect about 50 planets as small as Earth in the habitable zones of their stars, assuming stars have both an Earth- and a Venus-size planet. They’ll detect hundreds if most stars have smaller planets close-in and if there is an abundance of super-Earth-size planets.
These discoveries would be a clear indication that planets like ours are common in our galaxy. But, says Koch, not finding those 50 planets will also be a meaningful result. “If we expect 50 and we get nothing, or 1 or 2, then we can say, you can know, Earth-like planets are not common. Just as profound a result.” In either case, once its four-year mission is complete, scientists will have a far more detailed picture of the distribution of planets in our galaxy than they do now.
...Kepler will have 42 CCDs, each about 1 x 2 inches, containing a total of 95 megapixels. By comparison, the CCDs on digital cameras are about the size of a thumbnail and even top-of-the-line professional cameras typically contain about 10 to 12 megapixels. ...The launch is scheduled for February 2009.
2008 Mar 3. Creating a "phone-book for ET". By Gideon Bradshaw, BBC News. Excerpt: ...in early 2007, a Swiss team of astronomers led by Professor Stephan Udry working at the European Southern Observatory in northern Chile ... identified the smallest planet orbiting a main sequence star yet found in our galaxy... Gliese 581c. It was only five and a half times the mass of our Earth and seemed to be at just the right distance from its star to be habitable. ...Other scientists are more sceptical. Professor Geoff Marcy is the world's most prolific planet hunter. ...He too has studied G581c and is convinced that it is not habitable.
So, the hunt for the first incontrovertible Earth-like planet continues, and a new competitor is about to enter the race. ...In 2009 Nasa will launch Kepler, a space telescope with a mission to seek out new worlds. Horizon visited the factory where Kepler is being built, in the company of its creator, Dr Bill Borucki. ...Kepler is designed to be sensitive enough to detect Earth-like planets from day one. It will scan an incredible 100,000 stars day and night for four years.
After this time, we will know for sure just how common Earths are in the Milky Way.
Nasa's most pessimistic calculations predict that at least 50 Earth-like planets should exist within this collection of stars.
This would be the first galactic map of Earth-like planets, a "phone-book for ET".
2008 Feb 25. NASA to search galaxy for 'earthlike' planets. By Wayne Freedman, ABC7. Excerpt: MOUNTAIN VIEW, CA (KGO) -- Of all the digital cameras on planet Earth, you have never seen one like this. David Koch, an astronomer at NASA Ames in Mountain View, has just concluded a series of experiments that will open one pane in a window to the stars. It's a space-based telescope called Kepler. It will focus on a small section of our Milky Way Galaxy, searching for places where life might be.
ABC7 Reporter Wayne Freedman: "You're the man who will discover the first earthlike planet?"
Dr. David Koch: "That's right. That's the whole reason for doing this mission...."
2008 Feb 21. NASA Ames Conducts Tests of Kepler Mission Image Detectors. Space Ref (press release) - USA. Sensitive detectors that may help find habitable planets orbiting distant stars as part of NASA's Kepler Mission are undergoing tests at Ames Research .... See also Universe Today article.
2008 Jan 1. Wielding a Cost-Cutting Ax, and Often, at NASA. By WARREN E. LEARY, NY Times. Excerpt: WASHINGTON - In Washington, it almost seems radical - completing government projects at their original budgeted cost.
...In his eight months on the job, the director, S. Alan Stern, has turned back almost a half-dozen requests for more money from projects experiencing cost overruns, he said. That has forced mission leaders to trim parts of their projects, streamline procedures or find other sources of financing.
...NASA devotes about $5.4 billion a year to its science program, divided among specialties like astrophysics, earth science and planetary exploration. To finance President Bush's exploration initiative to return humans to the Moon, while also financing space shuttle operations and a shuttle replacement out of the agency's approximately $16 billion annual budget, science program money is being held to about a 1 percent increase per year for four years.
Factoring in inflation and the loss of what had been anticipated financing increases, space experts say this amounts to a loss for NASA science of about $3 billion over that period.
...One of the first targets in his effort to attack cost overruns was the Kepler mission, a project started in 2001 to launch a planet-hunting telescope. Because of management problems, technical issues and other difficulties, the price tag went up and the launching date slipped from the original 2006 target.
In 2006, NASA resolved itself to a 20 percent cost overrun, which raised the price to $550 million, and accepted a 2008 launching time. Then the Kepler team came to Dr. Stern last spring with a request for an additional $42 million.
"Four times they came for more money and four times we told them 'no,'" Dr. Stern said.
After Dr. Stern's team threatened to open the project to new bids so other researchers could take it over using the equipment that had already been built, the Kepler group came up with a solution. Among other measures, the duration of the four-year mission was cut by six months and preflight testing was scaled back.
"When they came to believe I was serious and had my boss's backing," Dr. Stern said, "they took it seriously. They quickly found a way to erase that bill."....
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