Astronomy Picture of the Day Search Results for "spirit mars"

APOD: 2009 January 20 - Bonestell Panorama from Mars
Explanation: If you could stand on Mars -- what could you see? One memorable vista might be the above 360-degree panoramic image taken by the robotic Spirit rover over the last year. The above image involved over 200 exposures and was released as part of Spirit's five year anniversary of landing on the red planet. The image was taken from the spot that Spirit stopped to spend the winter, near an unusual plateau called Home Plate. Visible on the annotated image are rocks, hills, peaks, ridges, plains inside Gusev crater, and previous tracks of the rolling Spirit rover. The image color has been closely matched to what a human would see, and named for the famous space artist Chesley Bonestell.

APOD: 2009 January 10 - Martian Sunset
Explanation: This month, the Mars Exploration Rovers are celebrating their 5th anniversary of operations on the surface of the Red Planet. The serene sunset view, part of their extensive legacy of images from the martian surface, was recorded by the Spirit rover on May 19, 2005. Colors in the image have been slightly exaggerated but would likely be apparent to a human explorer's eye. Of course, fine martian dust particles suspended in the thin atmosphere lend the sky a reddish color, but the dust also scatters blue light in the forward direction, creating a bluish sky glow near the setting Sun. The Sun is setting behind the Gusev crater rim wall some 80 kilometers (50 miles) in the distance. Because Mars is farther away, the Sun is less bright and only about two thirds the size seen from planet Earth.

APOD: 2008 June 29 - Shadow of a Martian Robot
Explanation: What if you saw your shadow on Mars and it wasn't human? Then you might be the Opportunity rover currently exploring Mars. Opportunity and sister robot Spirit have been probing the red planet since early 2004, finding evidence of ancient water, and sending breathtaking images across the inner Solar System. Pictured above, Opportunity looks opposite the Sun into Endurance Crater and sees its own shadow. Two wheels are visible on the lower left and right, while the floor and walls of the unusual crater are visible in the background. Opportunity and Spirit have now spent over four years exploring the red world, find new clues into the wet ancient past of our Solar System's second most habitable planet.

APOD: 2008 May 19 - Flying Over the Columbia Hills of Mars
Explanation: What it would be like to fly over Mars? Combining terrain data from the orbiting Mars Reconnaissance Orbiter spacecraft with information about the robotic Spirit rover currently rolling across Mars has resulted in a digital movie that shows what a flight over the Columbia Hills might look like. Dark rippled sand dunes are highlighted against the Columbia Hills in the above opening image. Clicking on the above image, though, will launch you across Mars, approaching the Columbia Hills. On the far side of the hills, the dark sand dunes come into view. Soon you pass an unusual white-rimmed structure, slightly raised, known as Home Plate, the origin of which is currently unknown and being researched. Turning, you re-approach the hills from a different angle, this time zooming in on Spirit, a curious alien rover sent from planet Earth. A final zoom pans out over the region. This coming Sunday, NASA's Phoenix Lander will attempt to set down near the icy North Pole of Mars and search for signs of ancient life.

APOD: 2008 January 29 - West Valley Panorama from the Spirit Rover on Mars
Explanation: What does Mars look like from here? Last September, before hiking across rugged and slippery terrain to reach its winter hibernation point, the robotic Spirit rover climbed a small plateau known as Home Plate and captured the spectacular vista pictured above. Part of the curious flat-topped Home Plate is visible as the light colored landscape across the panorama's foreground. On the image left, visible about eight kilometers in the distance, is Grissom Hill, while on the left foreground is rock strewn Tsiolkovski Ridge. On the right, at about 800 meters distant, is Husband Hill, already explored by Spirit and notable as the highest point visible in the westward looking panorama. In the inset is a close-up of a tiny motionless feature informally dubbed Little Bigfoot that has drawn some attention for it superficial appearance to a humanoid life form. Tenacious image explorers might locate Little Bigfoot towards the front left of the high resolution panorama. Spirit successfully reached its energy-conserving winter haven in December.

APOD: 2007 December 18 - Unusual Silica Rich Soil Discovered on Mars
Explanation: You're rolling across Mars when you unexpectedly uncover some unusually light soil. You stop. You turn. You return to inspect the soil and find out it is almost purely silica -- the main ingredient in quartz and glass. Such soil has never been found on Mars before. What created this soil? Since you are the robotic rover Spirit currently rolling across Mars, you send the images and data back to Earth for analysis. Your scientist friends from the blue water planet say that such soil on Earth is usually created by either volcanic steam or a hot spring. The second hypothesis in particular indicates, once again, a wet past for part of Mars, as possibly hot water saturated with silica deposited the white soil. Intriguingly, on Earth, living microbes typically flourish under either condition. Pictured above, the uncovered light soil is visible on the right.

APOD: 2007 December 12 - Mars Rover Races to Survive
Explanation: The Martian rover Spirit is now in the race of its life. The rolling robot is trying to reach an outpost to spend the winter, but it keeps getting bogged down in soft sand on Mars. Earth scientists hope that Spirit can reach a slope on the northern edge of the unusual feature dubbed Home Plate, before the end of this month when northern winter will be phasing in on Mars. Reaching this slope will likely allow the rover to tilt enough toward the Sun to create a needed increase in the efficiency of its energy-absorbing solar panels. This map shows the path of Spirit from July 2004 until just last month.

APOD: 2007 August 5- The Dotted Dunes of Mars
Explanation: What causes the black dots on dunes on Mars? As spring dawned on the Northern Hemisphere of Mars in 2004, dunes of sand near the poles begin to defrost. Thinner regions of ice typically thaw first revealing sand whose darkness soaks in sunlight and accelerates the thaw. The process might involve sandy jets exploding through the thinning ice. By summer, the spots expanded to encompass the entire dunes that were then completely thawed and dark. The carbon dioxide and water ice actually sublime in the thin atmosphere directly to gas. Taken in mid-July, the above image shows a field of spotted polar dunes spanning about 3 kilometers near the Martian North Pole. Today, the future of Mars rovers Spirit and Opportunity remains unknown windy dust storms continue to starve them of needed sunlight.

APOD: 2007 July 25 - Global Dust Storms Threaten Mars Rovers
Explanation: Will global dust storms terminate the robotic Martian rovers? Over the past month, windy dust storms have blocked much needed sunlight from reaching the solar panels of both the Spirit and Opportunity rovers exploring Mars. At times, as much as 99 percent of direct sunlight has been obscured, causing worry that the batteries might run out of energy before the storms end -- which may be as long as weeks. In an effort to weather these storms, Earth controllers have programmed the rovers to restrict movements and to use as little power as possible. Although the rovers have been working for a remarkable three years past their planned three month lifetimes, their immediate future is now uncertain. Pictured above, the Opportunity rover perched on the edge of Victoria Crater peered for a month into the distance as dust made the Martian air increasingly opaque.

APOD: 2007 March 13 - Attacking Mars
Explanation: The Spirit rover attacked Mars again in 2005 September. What might look, above, like a military attack, though, was once again just a scientific one - Spirit was instructed to closely inspect some interesting rocks near the summit of Husband Hill. Spirit's Panoramic Camera captured the rover's Instrument Deployment Device above as moved to get a closer look at an outcrop of rocks named Hillary. The Spirit rover, and its twin rover Opportunity, have now been exploring the red planet for over three years. Both Spirit and Opportunity have found evidence that parts of Mars were once wet.

APOD: 2007 February 4 - Shadow of a Martian Robot
Explanation: What if you saw your shadow on Mars and it wasn't human? Then you might be the Opportunity rover currently exploring Mars. Opportunity and sister robot Spirit have been probing the red planet since early 2004, finding evidence of ancient water, and sending breathtaking images across the inner Solar System. Pictured above, Opportunity looks opposite the Sun into Endurance Crater and sees its own shadow. Two wheels are visible on the lower left and right, while the floor and walls of the unusual crater are visible in the background. Opportunity and Spirit have now spent over three years exploring the red world, find new clues into the wet ancient past of our Solar System's second most habitable planet.

APOD: 2006 December 6 - Spirit Rover on Mars Imaged from Orbit
Explanation: If you have the right equipment, you can see the Spirit rover currently rolling across Mars. The right equipment, however, is currently limited to the High Resolution Imaging Science Experiment onboard the Mars Reconnaissance Orbiter (MRO). MRO arrived at Mars in March and just started science observations of the red planet last month. Visible in the above spectacularly high resolution image is the Spirit rover in the Columbia Hills of Mars. Objects as small as one meter are resolved. Also visible are the tracks made by the robot explorer and a large plateau of layered rock dubbed Home Plate. MRO will continue to image the red planet in unprecedented detail, creating images that will likely be important in better understanding the geology and weather on Mars, as well as indicating good candidate landing sites for future missions to Mars.

APOD: 2006 November 1 - McMurdo Panorama from Mars
Explanation: This was Spirit's view on Martian-day 1,000 of its 90-Martian-day mission. The robotic Spirit rover has stayed alive so long on Mars that it needed a place to wait out the cold and dim Martian winter. Earth scientists selected Low Ridge hill, a place with sufficient slant to give Spirit's solar panels enough sunlight to keep powered up and making scientific observations. From its Winter Haven, Spirit has been able to build up the above 360-degree panorama, which has been digitally altered to exaggerate colors and compressed horizontally to fit your screen. The long winter is finally ending in the south of Mars, and with the increasing sunlight plans are now being made for Spirit to further explore the rocky Columbia Hills inside intriguing Gusev crater.

APOD: 2006 August 4 - Burns Cliff Anaglyph
Explanation: Get out your red/blue glasses and gaze across Burns Cliff along the inner wall of Endurance crater on Mars! The view from the perspective of Mars rover Opportunity is a color anaglyph - two different images are presented to the left and right eyes by color filters to produce the 3D effect. Scroll the picture to the right to see the full 180 degree panorama. Still returning science data and images, both Spirit and Opportunity rovers completed 2 years of Mars exploration in January. Opportunity spent the month of July on the road to Victoria crater. The stereo pair of images used to create this view are based on image data recorded in November 2004.

APOD: 2006 July 21 - Strangers on Mars
Explanation: This view from the winter station of Mars Exploration Rover Spirit, looks across the rock strewn landscape of Gusev Crater. The dark boulders and distant hills are characteristic of the region, but the two light colored rocks in the foreground of this cropped image are - like Spirit itself - most probably strangers to the Red Planet, believed to be iron meteorites. Informally named for sites in Antarctica they have been dubbed "Zhong Shan" and "Allan Hills." Zhong Shan is the Antarctic base of the People's Republic of China. Allan Hills is the icy location where many Martian meteorites have been found on planet Earth, including the controversial ALH84001, suggested to contain evidence for fossilized Martian microbial life.

APOD: 2006 July 3 - The View toward Husband Hill on Mars
Explanation: This Martian vista is only part of one of the greatest panoramic views of Mars that has ever been attempted. The expansive mosaic is helping to keep the robotic Spirit rover busy over the energy draining winter in the southern hemisphere of Mars. During the winter, Spirit is constrained to stay on the side of McCool Hill in order to keep its solar panels pointed toward the Sun. The panorama has so far involved over 800 exposures, very little digital compression, and will take over a month to complete. The view shown is toward Husband Hill, a hill that Spirit climbed last year. A careful inspection of the above image shows tracks crossing from the center to the right.

APOD: 2006 June 5 - The Road to Victoria Crater on Mars
Explanation: Here is a road never traveled. To get to Victoria Crater on Mars, the rolling robotic rover Opportunity must traverse the landscape shown above. Victoria Crater lies about one kilometer ahead. The intervening terrain shows a series of light rock outcrops that appears like some sort of cobblestone road. Surrounding this naturally-occurring Martian road, is Martian sand ripples that must be navigated around. Inspection of the outcrop road shows it to be sprinkled with many small round rocks dubbed blueberries. Opportunity and its sister robot Spirit continue their third year exploring Mars. Within the next month, planetary scientists hope to maneuver Opportunity across Meridiani Planum to get a good view of 800-meter diameter Victoria Crater.

APOD: 2006 May 15 - Volcanic Bumpy Boulder on Mars
Explanation: What created this unusually textured rock on Mars? Most probably: a volcano. Dubbed Bumpy Boulder, the strange stone measuring just under a half-meter high was found by the robotic Spirit rover currently rolling across Mars. Pits on the ragged rock are likely vesicles and arise from hot gas bubbling out of hot rock ejected by an active Martian volcano. Several similar rocks are visible near Bumpy Boulder that likely have a similar past. The above true-color image was taken about one month ago. The Spirit rover, now in its third year of operation on Mars, is weathering the low sunlight winter of Mar's northern hemisphere on a hillside slope in order to maximize the amount of absorbable battery-refreshing sunlight.

APOD: 2006 April 6 - Unusual Bright Soil on Mars
Explanation: What is this bright soil on Mars? Several times while rolling across Mars, the treads of the robotic rover Spirit have serendipitously uncovered unusually bright soil. Spirit uncovered another batch unexpectedly last month while rolling toward its winter hibernation location on McCool Hill. The physics and chemistry instruments on Spirit have determined the soil, shown above, contains a high content of salts including iron-bearing sulfates. A leading hypothesis holds that these salts record the presence of past water, with the salts becoming concentrated as the water evaporated.

APOD: 2006 March 15 - McCool Hill on Mars
Explanation: You can make it. Winter is rapidly advancing on the southern hemisphere on Mars, and the lack of sunlight could be dangerous unless you find a good place to hibernate. There it is ahead: McCool Hill. As the robotic Spirit rover rolling across Mars, you are told that this will be a good place to spend the Martian winter. On the north slope of McCool Hill, you can tilt your solar panels toward the Sun enough to generate the power you need to keep running through the winter. Between you and McCool Hill is an unusual reddish outcropping of rocks. Also visible above, unusual layered rocks lie to your right, while other scattered rocks appear either smooth or sponge-like. Fortunately, there is still some time to explore, and the landscape before you may hold more clues to the history of ancient Mars.

APOD: 2006 January 26 - An Unusual Two Toned Rock on Mars
Explanation: How did this unusual Martian rock form? The atypical two-toned rock, visible in the lower right of the above image, was photographed a few days ago by the robotic Spirit rover currently rolling across Mars. For now, the environmental processes that created the rock remain a matter of speculation. Finding unusual rocks is not unusual for Spirit or its twin rover Opportunity, however. Over the past two years, for example, the rovers have unexpectedly discovered very small gray pebbles dubbed blueberries, and a rock out in the middle of nowhere now thought to be a meteorite. Having investigated alien terrain and having found clear evidence that part of Mars had a wet past, the Earth-launched Martian rovers are now entering their third spectacular year exploring the red planet.

APOD: 2006 January 5 - New Year Mars Panorama
Explanation: According to an Earth-based calendar, the Spirit rover spent the first day of 2006 gathering data to complete this panoramic view from Gusev crater on Mars. That day corresponded to Spirit's 710th Martian day or sol on the Red Planet. Scrolling right the view spans 160 degrees, looking up a slope and across rippled sand deposits in a dark field dubbed "El Dorado". The Spirit rover is traveling in a down hill direction after reaching the summit of Husband Hill. This month, both Spirit and Opportunity rovers will celebrate two years of Mars exploration, a remarkable achievement considering their original 90 day warranty. During that time Spirit has traveled over 3.5 miles and Opportunity over 4 miles across the Martian surface.

APOD: 2005 December 14 - A Digital Opportunity Rover on Mars
Explanation: If you could see one of the robot rovers currently rolling across Mars, what would it look like? To gain this perspective useful in planning explorations, the above synthetic image was produced digitally. Above, a digital model of the Opportunity rover was added to a real image of the inside of Endurance Crater on Mars taken earlier by Opportunity itself. The size of the six-wheeled robot was scaled to the size of the tracks that the Opportunity rover actually created. In actuality, both the Opportunity and Spirit rovers currently rolling across Mars each span about two meters and so are similar in size to a large rolling desk. Also visible in the image is dark soil, ancient light rock and numerous small gray pellets known as blueberries.

APOD: 2005 November 28 - Vista Inside Gusev Crater on Mars
Explanation: What is the geologic history of Mars? To help find out, the robot Spirit rover explored the terrain on the way up to the top of Husband Hill and took pictures along the way. Earth-bound team members later combined images from one camera with colors from another to create this semi-realistic vista from near the top of the rugged hill. Many rock faces were imaged and probed along the way. The above image captures not only a high and distant Mars inside Gusev crater, but also more of the refrigerator-sized Spirit rover than other similar vistas. Visible technology includes a wide array of energy-absorbing solar panels, a sundial, and the circular high gain communications antenna.

APOD: 2005 November 14 - Everest Panorama from Mars
Explanation: If you could stand on Mars -- what might you see? Scroll right to find out. The robotic Spirit rover currently rolling across Mars climbed to the top of hill and took a series of images that were digitally combined into a 360 degree panorama over three days early last month. Spirit was instructed to take images having the same resolution as a human with 20-20 eyesight. The full panoramic result can be found by clicking on the above image and has a level of detail unparalleled in the history of Martian surface photography. The panorama was taken from the pinnacle of Husband Hill and has been dubbed the Everest panorama, in honor of the view from the tallest mountain on Earth. Visible in Gusev Crater are rocks, rusting sand, a Martian sundial, vast plains, nearby peaks, faraway peaks, and sand drifts. In the distance, fast moving dust devils can be seen as slight apparitions of red, green, or blue, the colors of filters used to build up this natural color vista.

APOD: 2005 October 24 - Angular Sand on Martian Hills
Explanation: Why isn't this sand round? The robotic Spirit rover currently rolling across Mars has found notably angular sand in the Columbia Hills on Mars. Previously, small bits of sand found in the plains of Gusev Crater were significantly more round. The finding indicates that angular hill sand has tumbled less and likely traveled a shorter distance than the corresponding round plain sand. Such tumbling has the general effect of making sand and rocks increasingly round and with fewer sharp edges. Pictured above, as taken last month, are angular sand grains magnified by Spirit's Microscopic Imager. The above frame spans about three centimeters.

APOD: 2005 September 7 - The View from Husband Hill on Mars
Explanation: Scroll right to see a breathtaking panorama of Mars from the top of Husband Hill. The image was taken by the robotic rover Spirit now exploring the red planet. Spirit, situated in expansive Gusev Crater, has been exploring the Columbia Hills for some time including climbing Husband Hill over the last few months. On the way up, Spirit took in a color vista from Larry's Lookout. Visible in the above image is the vast eastern landscape previously blocked from view by the Columbia Hills themselves. The horizon is mostly defined by the rim of Thira crater visible some 15 kilometers in the distance. Spirit will now examine rocks and soil at the top of Husband Hill, looking for clues as to how the hills and local rocks formed in the distant past.

APOD: 2005 June 20 - Sunset Over Gusev Crater
Explanation: What would it be like to see a sunset on Mars? To help find out, the robotic rover Spirit was deployed last month to park and serenely watch the Sun dip below the distant lip of Gusev crater. It was a tough job, but some robot had to do it. Now on Earth a red sunset is caused by two effects -- by blue light being preferentially scattered out of sunlight by oxygen and nitrogen molecules in the atmosphere, and by scattering off a small amount of impurities like volcanic dust. (The magnitude of the first effect was computed in one of Albert Einstein's most cited papers.) Although Mars lacks oxygen and nitrogen, it is covered in red dust frequently hoisted into the atmosphere by fast but thin winds. Analyses of images like the above photograph show that at least some Martian days are capped by a sunset significantly longer and redder than typical on Earth. For up to two hours after twilight, sunlight continued to reflect off Martian dust high in the atmosphere, casting a diffuse glow. The result helps atmospheric scientists understand not only the atmosphere of Mars, but atmospheres across the Solar System, including our home Earth.

APOD: 2005 May 17 - A Panorama of Mars from Larrys Lookout
Explanation: Scroll right to see a breathtaking panorama of Mars from Larry's Lookout. The lookout occurs near the peak of Husband Hill in the Columbia Hills. The summit of Husband Hill is visible 200 meters in the distance toward the center of the 360-degree near-true-color picture. The robot rover Spirit took images that compose the above mosaic over four Martian days. After taking the image sequence, Spirit carefully picked its way to toward Husband Hill's summit. On the far right, near distant rover tracks, is a recently investigated area dubbed Paso Robles that was found to contain high amounts of sulfur.

APOD: 2005 May 2 - Methuselah Outcrop on Mars
Explanation: What is the history of the outcropping of rock called Methuselah? The unusual rock group is visible on the left of the above image taken by the robot Spirit rover current exploring Mars. Methuselah was discovered while maneuvering over hilly terrain and shows unusual multiple layering that caught the attention of the rover science team. Since the above representative color image was taken about three weeks ago, Spirit has moved in to get a closer look. Also visible in the above image are another rock outcrop dubbed Larry's Lookout on the upper right and a larger Clark Hill in the left background. On the far right is a more distant peak of the Columbia Hills.

APOD: 2005 April 26 - A Martian Dust Devil Passes
Explanation: What goes there across the plains of Mars? A dust devil. For the first time, definitive movies of the famous spinning dust towers have been created from ground level. The robot rover Spirit has now imaged several dust devils from its hillside perch just within the past two months. Each image in the above sequence was taken about 20 seconds apart. Inspection of the digitally resized images show the passing dust devil raising Martian dust so thick that it casts a shadow. The new dust devil movies have been made possible by a new hybrid interaction system where the robot Spirit on Mars takes many images and humans on Earth inspect thumbnails and decide which full resolution images to send back.

APOD: 2005 April 12 - Earth or Mars?
Explanation: Which image is Earth, and which is Mars? One of the above images was taken by the robot Spirit rover currently climbing Husband Hill on Mars. The other image was taken by a human across the desert south of Morocco on Earth. Both images show vast plains covered with rocks and sand. Neither shows water or obvious signs of life. Each planet has a surface so complex that any one image does not do that planet justice. Understanding either one, it turns out, helps understand the other. Does the one on the left look like home? Possibly not, but it is Earth.

APOD: 2005 March 23 - A Dust Devil Swirling on Mars
Explanation: What is that wisp on the horizon? Scientists think that the slight white apparition is actually a Martian dust devil that was caught swirling across Mars. The above image was taken earlier this month by the robotic rover Spirit. The swirling cloud was found by comparing the above image to a previous image of the same area. Fresh dust devil tracks have been seen on Mars before, but actually seeing one up close was a surprise. The most similar phenomena to Martian dust devils on Earth are terrestrial dust devils, tornadoes and waterspouts. The ultimate cause of Martian dust devils remains unknown, but might be related to rising air heated by sun-warmed rocks and soil. Just the previous day, Spirit's power acquisition increased unexpectedly, possibly the result of a dust devil passing near or over the Spirit rover and effectively cleaning its solar panels.

APOD: 2004 December 31 - A Year of Mars Roving
Explanation: Landing on Mars in January, NASA's twin rovers Spirit and Opportunity have now each spent over 330 sols roving the martian surface. Still healthy and well in to extended missions, the golfcart sized robots have operated five times longer than planned. Ranging across the floor of Gusev crater, the Spirit rover has reached the Columbia Hills and journeyed nearly four kilometers. Half a planet away, Opportunity has spent much of its tour on Meridiani Planum exploring the 130 meter wide Endurance Crater. Opportunity recently returned this panoramic view of rock outcrops and steep crater walls. Both rovers have uncovered strong evidence that ancient salty oceans left their mark on the alluring Red Planet.

APOD: 2004 December 15 - Looking Back Over Mars
Explanation: Pictured above, the path of the robot rover Spirit on Mars can be traced far into the distance. Spirit has now crossed kilometers of plains covered with rocks and sand, approached the lip of a crater 200-meters across, and climbed a series of hills. Spirit's path has been not only one of adventure but discovery. Landing inside vast Gusev crater near the beginning of this year, Spirit, along with its sister robot Opportunity across the planet, has uncovered key evidence for ancient Martian water. The recent discovery of goethite, a mineral only known to form on Earth in the presence of water, bolsters the case. Spirit and Opportunity continue to roam the red planet in search of different and more detailed clues to the unfolding ancient past of Mars.

APOD: 2004 September 22 - Spirit Rover at Engineering Flats on Mars
Explanation: Is it art? Here the paintbrush was the Spirit robotic rover, the canvas was the soil on Mars, and the artists were the scientists and engineers of the Mars Exploration Rover Mission. The picture created was mostly unintentional -- the MERS team was primarily instructing Spirit to investigate rocks in and around Hank's Hollow in a location called Engineering Flats on Mars. After creating the ground display with its treads, the Spirit rover was instructed to photograph the area along with itself in silhouette. Both Mars rovers, Spirit and Opportunity, are now back in contact after an expected radio blackout caused by Mars moving behind the Sun. NASA has also announced that it is extending the rovers missions for six months, so long as they keep working.

APOD: 2004 August 23 - Looking Out Over Mars
Explanation: What would it be like to climb a hill and look out over Mars? That opportunity was afforded the Spirit rover earlier this month as it rolled to a high perch in the Columbia Hills. Peering out, the rolling robot spied the interior plains and distant rim of Gusev Crater, beyond an outcrop of rocks called Longhorn. Spirit continues to find evidence that many rock shapes have been altered by ancient water. Both Spirit and her sister robot Opportunity have completed their primary three-month mission but remain in good enough condition to continue to explore Mars.

APOD: 2004 August 3 - Shadow of a Martian Robot
Explanation: What if you saw your shadow on Mars and it wasn't human? Then you might be the Opportunity rover currently exploring Mars. Opportunity and sister robot Spirit have been probing the red planet since January, finding evidence of ancient water, and sending breathtaking images across the inner Solar System. Pictured above, Opportunity looks opposite the Sun into Endurance Crater and sees its own shadow. Two wheels are visible on the lower left and right, while the floor and walls of the unusual crater are visible in the background. Opportunity is cautiously edging its way into this enigmatic crater, hoping to find new clues into the wet ancient past of our Solar System's second most habitable planet.

APOD: 2004 July 19 - Attacking Mars
Explanation: The Spirit rover attacked Mars again late last month. What might look, above, like a military attack, though, was once again just a scientific one - Spirit was instructed to closely inspect some interesting rocks near Columbia Hills. Spirits Front Hazard Avoidance Camera captured the rover's Instrument Deployment Device above as it guided the Microscopic Imager to get a closer look at a rock dubbed Breadbox. Images taken by the Microscopic Imager show a rock surface consistent with basalt corroded by ancient groundwater. Structures with similar origins can be found, for example, in the Western Desert of Egypt on Earth. The above picture taken on June 30, the 175th Martian day that the Spirit rover has been on the red planet.

APOD: 2004 June 28 - Spirit Rover Reaches the Columbia Hills on Mars
Explanation: The Spirit robotic rover on Mars has now reached the Columbia Hills on Mars. Two of the hills are shown on approach near the beginning of June. The above true-color picture shows very nearly what a human would see from Spirit's vantage point. The red color of the rocks, hills, and even the sky is caused by pervasive rusting sand. Spirit has now traveled over 3 kilometers since it bounced down onto the red planet in January. The robotic explorer, controlled and programmed remotely from Earth, is now investigating a rock called Pot of Gold. On the other side of Mars, Spirit's twin Opportunity is now inspecting unusual rocks inside a pit dubbed Endurance crater.

APOD: 2004 May 19 - Brain Crater on Mars
Explanation: What caused this unusual looking crater floor on Mars? Appearing at first glance to resemble the human brain, the natural phenomena that created the unusual texture on the floor of this Martian impact crater are currently under investigation. The light colored region surrounding the brain-textured region is likely sand dunes sculpted by winds. The Mars Global Surveyor robot spacecraft that has been orbiting Mars since 1997 took the above image. Meanwhile, down on the surface, robots Spirit and Opportunity continue to roll, inspecting landscape, rocks, and soil for clues to the ancient watery past of the red planet. Humorously, this brain-terrain on Mars spans about a kilometer, making it just about the right size to fit inside the rock formation once dubbed the Face on Mars.

APOD: 2004 May 4 - Missoula Crater on Mars
Explanation: Scroll right to see the rocks, craters, and hills that were in view for the Spirit rover last week as it continued its trek across Mars. Missoula crater, taking up much of the above frame, appeared from orbit to have ejecta from Bonneville crater inside it. Upon closer inspection, however, Spirit finds only evidence for wind-blown drifts. The rocks show numerous blisters and small cavities that may have occurred as ancient water vapor evaporated from hot cooling lava. Columbia Hills in the distance is now planned as the ultimate destination for the Spirit rover. Both of the Mars rovers have now successfully completed their original mission and are now exploring topical opportunities.

APOD: 2004 April 1 - April Fools Day More Intense On Mars
Explanation: Today, April 1st, astrophysicists have announced a surprising discovery - April Fools Day is more intense on Mars! Though the discovery is contrary to accepted theories of April Fools Day, researchers note that there are several likely causes for the severe martian April Fools phenomenon. For starters, gravity, the force that opposes comedy throughout the universe, is only about 3/8ths as strong on Mars' surface as it is on planet Earth. Also, a martian day, called a sol, lasts nearly 40 minutes longer than an earth day. And furthermore ... well, as soon as they think of some more reasons, they've promised to tell us. Happy April Fools day from the editors at APOD! Editors note: Mars rover Spirit recorded this image looking out toward the eastern horizon and the Columbia Hills over 2 kilometers in the distance. Its journey across this rocky martian terrain could take from 60 to 90 sols.

APOD: 2004 March 18 - Spirit Pan from Bonneville Crater's Edge
Explanation: Scroll right and follow this breathtaking view of the martian surface from the southern edge of a small crater dubbed Bonneville. NASA's Spirit rover recorded the sharp 180-degree panorama on sols 68 and 69 of its stay on the Red Planet, following the completion of a 300+ meter journey from its landing site within Mars' expansive Gusev Crater region. Bonneville crater itself is about 200 meters across. Rocks scattered about the area are potentially "ejecta" from Bonneville, debris blasted from below the martian surface by the impact which created the crater. Researchers are eager to confirm this scenario since such material could be a guide to the geological history of the area. So what's that shiny patch on the left, just beyond the crater's far rim? It's the Spirit lander's heat shield.

APOD: 2004 March 10 - Humphrey Rock Indicates Ancient Martian Water
Explanation: How prevalent was water on Mars? Results from the Spirit rover now indicate that Gusev crater likely had a wet past, a result that comes shortly after Spirit's twin rover Opportunity uncovered clear evidence of past water at Meridiani Planum on the other side of Mars. Evidence uncovered by Spirit and released last week focussed on a large rock of unusual shape nicknamed Humphrey, shown above near the image bottom. Detailed inspection of the rock revealed a bright material filling internal cracks. Such material may have crystallized from water trickling through the volcanic rock. The amount of Mars once covered by ancient water remains unknown, as both rovers landed in regions thought likely to once be underwater. Spirit continues to roll across Mars, recently passing the 300-meter mark on its way to Bonneville crater.

APOD: 2004 February 25 - White Boat Rock on Mars
Explanation: What caused this rock to have an unusual shape? Earlier this month the robot Spirit rover on Mars stopped to examine a rock dubbed "white boat", named for its unusually light color and shape. White boat, the large rock near the image center of the above color-composite image, was examined by Spirit just after Adirondack, a football-sized rock determined to be composed of volcanic basalt. Spirit resumed scientific operations two weeks ago after recovering from a computer memory problem. Spirit and its twin rover Opportunity, on the other side of Mars, continue to roam the red planet in search of clues to the ancient past of Earth's most hospitable neighbor.

APOD: 2004 February 4 - Opportunity's Horizon
Explanation: Remarkably, the Opportunity Mars rover lies in a small martian impact crater about 3 meters deep and 22 meters wide. For 360 degrees, Opportunity's horizon stretches to the right in this new color mosaic image from the rover's panoramic camera. Notable in this view of the generally dark, smooth terrain are surface imprints left by the lander's airbags and an outcropping of light-colored, layered rock about 8 meters away toward the northwest. Though they look imposing, the rocks in the tantalizing outcrop are only a few centimeters high and will be dwarfed by the cart-sized rover itself during future close-up investigations. Opportunity has now rolled off its lander and, along with the restored Spirit rover, is directly exploring the martian surface.

APOD: 2004 January 26 - A Landing at Meridiani Planum
Explanation: After an interplanetary journey of nearly 300 million miles, Opportunity bounced down on the martian surface at about 9:05 pm PST Saturday, its final plunge cushioned by airbags. Now the second NASA rover on Mars, Opportunity's landing site at Meridiani Planum is on the opposite side of the red planet from its twin rover Spirit. Described as unlike any ever seen on Mars, the dark, undulating terrain at Meridiani Planum (aka Terra Meridiani) is pictured above in the first stunning color view from Opportunity. This area is thought to be rich in gray hematite, an iron-bearing mineral which can form in watery environments. Part of the rover's deck is in the foreground while circular impressions and drag marks made by the airbags are visible just beyond it.

APOD: 2004 January 24 - Valles Marineris from Mars Express
Explanation: Looking down from orbit on January 14, ESA's Mars Express spacecraft scanned a 1700 by 65 kilometer swath across Valles Marineris - the Grand Canyon of Mars - with its remarkable High Resolution Stereo Camera. This spectacular picture reconstructs part of the scanned region from the stereo colour image data recording the rugged terrain with a resolution of 12 metres per pixel. Joining Mars Global Surveyor and Mars Odyssey, Mars Express has been orbiting the red planet since December 25th, returning scientific data, acting as a communications relay, and even making coordinated atmospheric observations with NASA's Spirit rover on the surface. The Beagle 2 lander was released from Mars Express making a landing attempt also on December 25th, but no signal has been received so far.

APOD: 2004 January 22 - Columbia Memorial Station
Explanation: After leaving its nest, the Spirit rover turned to capture this spectacular view over the Columbia Memorial Station and the floor of Gusev crater on the 16th sol of its visit to Mars. The sharp picture looks toward the northeast. Over 2 meters wide, the lander platform surrounded by deflated airbags, and the egress ramp used by the rover to complete its journey to the martian surface, are in the foreground. In the background lie Spirit's likely future waypoints and destination - initially toward a ridge on the left bordering an impact crater about 200 meters across and finally toward the hills visible on the horizon at the right. The crater is about 250 meters away while the hills are about 3 kilometers distant. Searching for evidence of ancient watery environments, Spirit's scientific instruments have begun to return data on the composition of the surface in the lander's vicinity, suggesting that iron-bearing volcanic minerals are present.

APOD: 2004 January 21 - Adirondack Rock on Mars
Explanation: Is this a great pyramid on Mars? Actually, the pictured rock dubbed Adirondack has an irregular shape, is only about the size of a football, and has formed by natural processes. Still, its relatively large size and dust-free surface made it the first destination for the robotic Spirit rover currently roving Mars. Spirit, itself the size of a golf cart, will now attempt to determine the rock's composition and history by prodding it with its sophisticated mechanical arm. Spirit's arm, programmed remotely from Earth, has the capability to bend, grind, and photograph the rock in minute detail. Spirit's twin rover Opportunity is scheduled to land on the other side of Mars this coming weekend.

APOD: 2004 January 18 - A Close-Up of Martian Soil
Explanation: Make your background the closest image of Mars yet. The Spirit Rover currently rolling on Mars has taken the highest resolution image to date of another planet. The above black and white image spans only about 1.5 centimeters across, with details smaller than 1/10 of a millimeter visible. A microscope attached to the Spirit rover's instrument arm took the image. Up close, the Martian soil appears to planetary geologists to have clumping properties similar to cocoa powder. As more images come in and as the Spirit Rover continues to explore Mars, more information about the unusual floor of Gusev Crater are likely to emerge.

APOD: 2004 January 16 - Martian Surface in Perspective
Explanation: Spirit moved across Mars yesterday as the rover successfully maneuvered down off its lander, driving its six wheels onto the floor of Gusev crater. As planned, the robotic geologist will now begin a close-up examination of the rocks and soil around the landing site for clues to the processes that formed them. A perspective projection of Spirit's local martian rocks and soil is shown above, based on 3D color image data recorded when rover was still perched on its landing platform. Dark-colored airbag drag marks stretch across the soil in this view of the surface. For scale, the triangular-faced rock in the upper left corner is about 20 centimeters (8 inches) high. Scientists anticipate that the rover's investigation will yield valuable evidence helping to confirm or refute the possibility that the floor of Gusev crater is an ancient lake bed.

APOD: 2004 January 14 - A Mars Panorama from the Spirit Rover
Explanation: If you could stand on Mars -- what would you see? Scrolling right will reveal a full color 360-degree panoramic view from NASA's Spirit Rover that landed on Mars just 10 days ago. The image is a digital mosaic from the panoramic camera that shows the view in every direction. Annotated on the image are the directions and distances to various hills along the horizon. These hills are valuable for orienting Spirit since they are also visible to the Mars Global Surveyor and Mars Odyssey spacecraft orbiting high overhead. Visible in the foreground are several instruments and airbags around Columbia Memorial Station. Spirit will attempt to roll onto the red planet in the next few days and explore interesting features.

APOD: 2004 January 13 - An Apollo 15 Panorama
Explanation: The Apollo 15 mission to Earth's Moon was dedicated to better understanding the surface of the moon by exploring mountains, valleys, maria, and highlands. Astronauts David Scott and James Irwin spent nearly three days on the Moon while Alfred Worden orbited above in the Command Module. The mission, which blasted off from Earth on 1971 July 26, was the first to deploy a Lunar Roving Vehicle. Pictured above in this digitally stitched mosaic panorama, David Scott examines a boulder in front of the summit of Mt. Hadley Delta. The shadow of James Irwin is visible to the right, while scrolling to the right will reveal a well-lit and diverse lunar terrain. The Apollo 15 mission returned about 76 kilograms of moon rocks for detailed study. Want to pan across the surface of Mars, too? Check out the color panoramic view from the Spirit landing site.

APOD: 2004 January 10 - Two Worlds, One Sun
Explanation: Two Worlds, One Sun, is the legend emblazoned on the Spirit rover's camera calibration target. Resting on the rover's rear deck, it also doubles as a sundial, allowing students to determine the solar time at Spirit's landing site on Mars. Examples of the sundial or Marsdial are shown above where the left image, captured near local noon, shows the effect of the Sun high in the martian sky. The right image from later in the afternoon with the Sun lower in the sky, shows a long shadow cast by the Marsdial's 3.5 centimeter high central post. Based on the computer generated grid overlay, students determined the local time in the central inset image to be about 12:17 pm local solar time. The face of the Marsdial was designed by astronomy artist Jon Lomberg in collaboration with other team members. Did you know, the Marsdial idea was a brainchild of Bill Nye, the Science Guy? Now you know ...

APOD: 2004 January 9 - Sol 5 Postcard from Mars
Explanation: A martian Sol - the average martian solar day - is about 39 minutes longer than Earth's familiar 24 hour day. Operating on martian time, the Spirit rover recently sent back this color postcard image, recorded on Sol 5 of its stay on the martian surface. This cropped version of the full, high-resolution mosaic looks north across Gusev crater floor. The smooth-looking, 9 meter wide circular feature dubbed Sleepy Hollow lies at the center of the scene. Within it are round dark markings which may have been left by the lander swaddled in airbags as it bounced across the martian surface. Other examples of disturbances, likely made by the lander's retracting airbags, can be seen in the foreground just beyond Spirit's solar cell covered deck.

APOD: 2004 January 8 - The Hills of Mars
Explanation: Distant hills rise above a rocky, windswept plain in this sharp stereo scene from the Spirit rover on Mars. When viewed with red/blue glasses, the picture combines left and right images from Spirit's high resolution panoramic camera to yield a dramatic 3D perspective. The hills were estimated to lie about 2 kilometers away and be approximately 50 to 100 meters high. Along with other features of the landscape, determining their direction and distance will help pinpoint the exact location of the Spirit landing site when compared with high resolution images of the region taken from Mars orbit. Much stereo image data, allowing important estimates of three dimensional shapes, sizes, and distances, is anticipated from the rover's cameras. (Editor's note: Red/blue glasses for viewing stereo pictures can be purchased or simply constructed using red and blue plastic for filters. Try it! To view this image, the red filter is used for the left eye.)

APOD: 2004 January 7 - Red Mars from Spirit
Explanation: Rocks are strewn across the broad, flat Gusev crater floor in this sharp color picture from NASA's Spirit rover. Recorded by the rover's panoramic camera, the picture is part of Spirit's first color image of Mars - the highest resolution picture yet taken on the surface of another planet. Already revealing alluring and perplexing details of an apparently windswept plain thought to be an ancient lake bed, this stunning view represents only a small fraction of the color image data mission scientists expect to be transmitted in the coming days. As the robotic Spirit rover is preparing to stand up, roll off the lander, and explore the geology of the crater floor, NASA has announced plans to rename the landing site the Columbia Memorial Station in honor of the astronauts lost in the Columbia space shuttle accident.

APOD: 2004 January 6 - Spirit's 3D View Toward Sleep Hollow
Explanation: Working late, tired mission members nicknamed the smooth-looking depression to the left of center in this image from the martian surface, Sleepy Hollow. The picture is a portion of the 3D panorama of the Spirit rover's landing site released yesterday, constructed with data from the Mars rover's navigation cameras. Use red/blue glasses, red for the left eye, to get the 3D effect. Sleepy Hollow is estimated to be around 9 meters (30 feet) in diameter and about 12 meters (40 feet) away. Possibly an impact crater, the martian surface feature is a tantalizing potential site for a future visit when the golf cart-sized robotic rover ventures forth. Covered with solar arrays, the rear deck of the rover is also visible in this view along with the top of an antenna at the right. An innovative camera calibration target, a martian sundial, can be seen left of the antenna, mounted near the edge of the rover's deck.

APOD: 2004 January 5 - Spirit Pan from Gusev Crater
Explanation: After a seven month voyage of nearly 500 million kilometers through interplanetary space, NASA's Spirit Rover has reached the surface of Mars. Scroll right and see a mosaic panorama of Spirit's first images returned from its landing site in Gusev Crater! Taken by Spirit's navigation camera, the panorama covers 360 degrees, with the spacecraft in the foreground and the floor of Gusev Crater, thought to be an ancient lake bed, extending to the horizon. The entry, descent, and landing phase of Spirit's mission - referred to by mission planners as "Six Minutes of Terror" - began Saturday night around 8:30pm PST as Spirit entered the martian atmosphere at about 20,000 kilometers per hour. Updates on Spirit's status will be posted throughout the day.

APOD: 2004 January 4 - Spirit Rover Bounces Down on Mars
Explanation: After a seven month voyage through interplanetary space, NASA's Spirit Rover has reached the surface of the Red Planet and returned the first images from its landing site in Gusev crater! The entry, descent, and landing phase of its mission - referred to by mission planners as "Six Minutes of Terror" - began Saturday night around 8:30pm PST as Spirit entered the martian atmosphere at about 12,000 miles per hour. Depicted in the above artist's illustration, the spacecraft is in the final stages of its landing sequence, swaddled in large, protective airbags and bouncing to a soft landing on Mars. The same type of airbags were used for the Mars Pathfinder landing in 1997. Updates on Spirit's status will be posted throughout the day.

APOD: 2003 September 22 - Opportunity Rockets Toward Mars
Explanation: Next stop: Mars. Two months ago, the second of two missions to Mars was launched from Cape Canaveral, Florida, USA above a Boeing Delta II rocket. The Mars Exploration Rover dubbed Opportunity is expected to arrive at the red planet this coming January. Pictured above, an attached RocketCam (TM) captures Opportunity separating from lower booster stages and rocketing off toward Mars. Upon arriving, parachutes will deploy to slow the spacecraft and surrounding airbags will inflate. The balloon-like package will then bounce around the surface a dozen times or more before coming to a stop. The airbags will then deflate, the spacecraft will right itself, and the Opportunity rover will prepare to roll onto Mars. A first rover named Spirit was successfully launched on June 10 and will arrive at Mars a few weeks earlier. The robots Spirit and Opportunity are expected to cover as much as 40 metres per day, much more than Sojourner, their 1997 predecessor. Spirit and Opportunity will search for evidence of ancient Martian water, from which implications might be drawn about the possibility of ancient Martian life.

APOD: 2003 August 15 - Sedimentary Mars
Explanation: High-resolution imaging of an area in the Schiaparelli Basin of Mars on June 3 by the MGS Mars Orbiter camera produced this stunning example of layered formations within an old impact crater. On planet Earth, such structures would be seen in sedimentary rock -- material deposited at the bottom of ancient lakes or oceans and then subsequently weathered away to reveal the layers. With the Sun shining from the left, the central layer appears to stand above the others within the 2.3 kilometer wide crater. The crater could well have been filled with water in Mars' distant past, perhaps resting at the bottom of a lake filling the Schiaparelli impact basin. Still, such layers might also have been formed by material settling out of the windy martian atmosphere. As satellites continue to examine the martian surface from orbit, NASA's Spirit and Opportunity spacecraft will attempt to land on on Mars early next year to further explore the tantalizing history of water on the Red Planet.

APOD: 2003 July 28 - Launch of the Spirit Rover Toward Mars
Explanation: Next stop: Mars. Last month the first of two missions to Mars was launched from Cape Canaveral, Florida, USA above a Boeing Delta II rocket. Pictured above, solid fuel boosters are seen falling away as light from residual exhaust is reflected by the soaring rocket. The Mars Exploration Rover dubbed Spirit is expected to arrive at the red planet this coming January. Upon arriving, parachutes will deploy to slow the spacecraft and surrounding airbags will inflate. The balloon-like package will then bounce around the surface a dozen times or more before coming to a stop. The airbags will then deflate, the spacecraft will right itself, and the Spirit rover will prepare to roll onto Mars. The robotic Spirit is expected to cover as much as 40 meters per day, much more than Sojourner, its 1997 predecessor. Spirit will search for evidence of ancient Martian water, from which implications might be drawn about the possibility of ancient Martian life. A second rover named Opportunity was successfully launched on July 7 and will arrive at Mars a few weeks later.

APOD: 2003 July 10 - Dust Storm Over Northern Mars
Explanation: Almost on cue, as Mars nears its closest approach to planet Earth in recorded history, ominous seasonal dust storms are beginning to kick up. Observers worry that the activity may presage the development of a planet wide dust storm, frustrating attempts to view Mars in the coming months, a situation similar to the Red Planet's uncooperative behavior in 2001. In this example, recorded in mid-May by the Mars Global Surveyor spacecraft camera, a dust storm the size of a continent sweeps north and east (toward the upper right) across Mars' northern Acidalia Planitia. Meanwhile, interplanetary robotic explorers Mars Express/ Beagle 2, Nozomi, and the twin Mars Exploration Rovers Opportunity and Spirit, are all bound for Mars and should arrive by early January 2004.