News, Updates, and Resources for Red Planet Mars

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Mars Will NOT Look As Big As the Full Moon (Universe Today article)
Mars made its closest approach ever in 2003, but it makes less close approaches every couple of years. Every time an e-mail circulates that Mars will look as big as the full moon. This was never true, and never will be. In 2003, Mars did make its closest approach to Earth in 50-60 thousand years, at about 56 million km on August 27, 2003.


Online Articles and News About Mars

  • 2021-02-06. Martian New Year on Sunday a second chance to start fresh, Earthling. By Chris Knight, The Telegram. Excerpt: ...Feb. 7 [2021] marks the beginning of [Martian] year 36. Back at the turn of the (Earth) century ...scientists decided they needed a way to count Martian years. Earth years wouldn’t do, since Mars takes 687 days to circle the sun. They picked the Martian spring equinox of 1955 as the start of year one. ...Mars, like Earth, has an elliptical orbit that brings it closer to the sun at certain points of the year. It also has an axial tilt of 25 degrees. (Earth’s is just over 23.) Together this creates seasons, with variations in temperature, sunlight and even air pressure, since some of the thin carbon dioxide atmosphere freezes at the poles in the winter. ...the overlap of tilt and orbit means northern Martian winters are significantly milder than in the south, with repercussions on any rovers operating in that hemisphere. ...Mars has its own days, commonly called sols. ...Nick Peper, a systems engineer on the team that operates the Curiosity rover, notes that a sol is almost the same length as a day, but that slight difference can cause problems. Earth’s day is 23 hours and 56 minutes long, the rounding of which gives us a leap day every four years. But a sol is 24 hours 39 minutes, or about 3% longer than a day. About once a month, the two line up briefly.  ...To keep Martian morning from drifting away from the actual sunrise, scientists merely lengthen each second, minute and hour on Mars by a factor of 1.02749. So a sol on Mars is 24 hours long, but every hour is a little long than its equivalent on Earth. It’s a good fix, though perhaps not as poetic as the one imagined by science-fiction author Kim Stanley Robinson, who in his Mars trilogy writes of “the timeslip,” when clocks stop every sol at midnight for 39 minutes. ...“It’s just close enough to lull you into thinking they’re the same length,” Peper says of Martian time units. “And just far enough apart to mess you up.” ...Curiosity recently passed its 3,000th sol on Mars.... []  See also Martian Time Lookup, Mars clock, and EarthSky article
  • Upcoming Martian New Years:
    37 - Dec 26 2022
    38 - Nov 12 2024
    39 - Sep 30 2026
    40 - Aug 17 2028
  • 2014-07-10. NASA Spacecraft Observes Further Evidence of Dry Ice Gullies on Mars. Excerpt: Repeated high-resolution observations made by NASA’s Mars Reconnaissance Orbiter (MRO) indicate the gullies on Mars’ surface are primarily formed by the seasonal freezing of carbon dioxide, not liquid water. The first reports of formative gullies on Mars in 2000 generated excitement and headlines because they suggested the presence of liquid water on the Red Planet, the eroding action of which forms gullies here on Earth. ...said lead author Colin Dundas of the U.S. Geological Survey's Astrogeology Science Center in Flagstaff, Arizona " we started to see more activity and pin down the timing of gully formation and change, we saw that the activity occurs in winter." ...researchers determined the timing of this activity coincided with seasonal carbon dioxide frost and temperatures that would not have allowed for liquid water. Frozen carbon dioxide, commonly called dry ice, does not exist naturally on Earth, but is plentiful on Mars. It has been linked to active processes on Mars such as carbon dioxide gas geysers and lines on sand dunes plowed by blocks of dry ice. One mechanism by which carbon dioxide frost might drive gully flows is by gas that is sublimating from the frost providing lubrication for dry material to flow. Another may be slides due to the accumulating weight of seasonal frost buildup on steep slopes. The findings in this latest report suggest all of the fresh-appearing gullies seen on Mars can be attributed to processes currently underway, whereas earlier hypotheses suggested they formed thousands to millions of years ago when climate conditions were possibly conducive to liquid water on Mars....  NASA Release 14-191.
  • 2013-03-12.    NASA Rover Finds Conditions Once Suited for Ancient Life on Mars.    NASA    RELEASE: 13-073    Excerpt: An analysis of a rock sample collected by NASA's Curiosity rover shows ancient Mars could have supported living microbes. Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon -- some of the key chemical ingredients for life -- in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater on the Red Planet last month. "A fundamental question for this mission is whether Mars could have supported a habitable environment," said Michael Meyer, lead scientist for NASA's Mars Exploration Program at the agency's headquarters in Washington. "From what we know now, the answer is yes." URL:
  • 2012-11-15. NASA Rover Providing New Weather and Radiation Data About Mars. NASA RELEASE: 12-402. Excerpt: Observations of wind patterns and natural radiation patterns on Mars by NASA's Curiosity rover are helping scientists better understand the environment on the Red Planet's surface. Researchers using the car-sized mobile laboratory have identified transient whirlwinds, mapped winds in relation to slopes, tracked daily and seasonal changes in air pressure, and linked rhythmic changes in radiation to daily atmospheric changes.  …"Dust in the atmosphere has a major role in shaping the climate on Mars," said Manuel de la Torre Juarez of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. … "The dust lifted by dust devils and dust storms warms the atmosphere."
    Dominant wind direction identified by REMS has surprised some researchers who expected slope effects to produce north-south winds. The rover is just north of a mountain called Mount Sharp. If air movement up and down the mountain's slope governed wind direction, dominant winds generally would be north-south. However, east-west winds appear to predominate. …REMS monitoring of air pressure has tracked both a seasonal increase and a daily rhythm. Neither was unexpected, but the details improve understanding of atmospheric cycles on present-day Mars, which helps with estimating how the cycles may have operated in the past. The seasonal increase results from tons of carbon dioxide, which had been frozen into a southern winter ice cap, returning into the atmosphere as southern spring turns to summer. The daily cycle of higher pressure in the morning and lower pressure in the evening results from daytime heating of the atmosphere by the sun. As morning works its way westward around the planet, so does a wave of heat-expanded atmosphere, known as a thermal tide.
    Effects of that atmospheric tide show up in data from Curiosity's Radiation Assessment Detector (RAD). This instrument monitors high-energy radiation considered to be a health risk to astronauts and a factor in whether microbes could survive on Mars' surface. Read full release:
  • 2012-03-07. NASA Mars Orbiter Catches Twister in Action.  NASA - High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. See image of an afternoon whirlwind on Mars lofting a twisting column of dust more than half a mile (800 meters) high and casting a shadow on the Martian ground.
  • 2011 Nov 2. NASA Study Of Clay Minerals Suggests Watery Martian Underground. NASA RELEASE : 11-369. Excerpt: ...A new NASA study suggests if life ever existed on Mars, the longest lasting habitats were most likely below the Red Planet's surface. A new interpretation of years of mineral-mapping data, from more than 350 sites on Mars examined by European and NASA orbiters, suggests Martian environments with abundant liquid water on the surface existed only during short episodes. These episodes occurred toward the end of hundreds of millions of years during which warm water interacted with subsurface rocks. This has implications about whether life existed on Mars and how its atmosphere has changed. "The types of clay minerals that formed in the shallow subsurface are all over Mars," said John Mustard, professor at Brown University in Providence, R.I. Mustard is a co-author of the study in the journal Nature. "The types that formed on the surface are found at very limited locations and are quite rare."
    Discovery of clay minerals on Mars in 2005 indicated the planet once hosted warm, wet conditions. If those conditions existed on the surface for a long era, the planet would have needed a much thicker atmosphere than it has now to keep the water from evaporating or freezing. Researchers have sought evidence of processes that could cause a thick atmosphere to be lost over time.
    This new study supports an alternative hypothesis that persistent warm water was confined to the subsurface and many erosional features were carved during brief periods when liquid water was stable at the surface.
    "Our interpretation is a shift from thinking that the warm, wet environment was mostly at the surface to thinking it was mostly in the subsurface, with limited exceptions," said Scott Murchie of Johns Hopkins University Applied Physics Laboratory in Laurel, Md., a co-author of the report and principal investigator for CRISM.
    Find more information about the Mars Reconnaissance Orbiter.
  • 2010 October 29. Liquid Water Found on Mars, But It's Still a Hard Road for Life. By Richard A. Kerr, Science. [Must be an AAAS member to read the full article] Excerpt: Researchers appear to have finally achieved one of the Phoenix lander's primary goals. After digging through piles of data left from the mission to Mars more than 2 years ago, they've discovered signs that liquid water has lately flowed on the frigid planet.
    …Phoenix team members report that liquid water—probably only thin films of it—appears to have concentrated salts onto small patches of soil that Phoenix uncovered. The water may be liquid every martian spring or summer, or perhaps it only melted many millennia ago….
  • 2010 September 9. NASA RELEASE 10-216: NASA Data Shed New Light About Water and Volcanoes on Mars. Excerpt: Data from NASA's Phoenix Mars Lander suggest liquid water has interacted with the Martian surface throughout the planet's history and into modern times. The research also provides new evidence that volcanic activity has persisted on the Red Planet into geologically recent times, several million years ago.
    Although the lander, which arrived on Mars on May 25, 2008, is no longer operating, NASA scientists continue to analyze data gathered from that mission. These recent findings are based on data about the planet's carbon dioxide, which makes up about 95 percent of the Martian atmosphere.
    ...Phoenix precisely measured isotopes of carbon and oxygen in the carbon dioxide of the Martian atmosphere. Isotopes are variants of the same element with different atomic weights... The paper explains the ratios of stable isotopes and their implications for the history of Martian water and volcanoes.
  • 2010 July 23. NASA RELEASE: 10-176. NASA Spacecraft Camera Yields Most Accurate Mars Map Ever. Excerpt: WASHINGTON -- A camera aboard NASA's Mars Odyssey spacecraft has helped develop the most accurate global Martian map ever. Researchers and the public can access the map via several websites and explore and survey the entire surface of the Red Planet... The map was constructed using nearly 21,000 images from the Thermal Emission Imaging System, or THEMIS, a multi-band infrared camera on Odyssey... The pictures have been smoothed, matched, blended and cartographically controlled to make a giant mosaic. Users can pan around images and zoom into them. At full zoom, the smallest surface details are 330 feet wide. 
    ...Working with THEMIS images from the new map, the public can contribute to Mars exploration by aligning the images to within a pixel's accuracy at NASA's "Be A Martian" website, which was developed in cooperation with Microsoft Corp. Users can visit the site at:
    ..."The Mars Odyssey THEMIS team has assembled a spectacular product that will be the base map for Mars researchers for many years to come," said Jeffrey Plaut, Odyssey project scientist at JPL. "The map lays the framework for global studies of properties such as the mineral composition and physical nature of the surface materials."
    ...Other sites build upon the base map. At Mars Image Explorer, which includes images from every Mars orbital mission since the mid-1970s, users can search for images using a map of Mars
    ..."The broad purpose underlying all these sites is to make Mars exploration easy and engaging for everyone," [Phillip] Christensen said. "We are trying to create a user-friendly interface between the public and NASA's Planetary Data System, which does a terrific job of collecting, validating and archiving data."
  • 2010 June 3. NASA RELEASE: 10-131. NASA Rover Finds Clue to Mars' Past and Environment for Life. Excerpt: PASADENA, Calif. -- Rocks examined by NASA's Spirit Mars Rover hold evidence of a wet, non-acidic ancient environment that may have been favorable for life. Confirming this mineral clue took four years of analysis by several scientists. …An outcrop that Spirit examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic.
    …"This is one of the most significant findings by the rovers," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is principal investigator for the Mars twin rovers, Spirit and Opportunity, and a co-author of the new report. "A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place.
    …Massive carbonate deposits on Mars have been sought for years without much success. Numerous channels apparently carved by flows of liquid water on ancient Mars suggest the planet was formerly warmer, thanks to greenhouse warming from a thicker atmosphere than exists now. The ancient, dense Martian atmosphere was probably rich in carbon dioxide, because that gas makes up nearly all the modern, very thin atmosphere.
  • 2010 May 26. NASA RELEASE: 10-122. NASA Spacecraft Penetrates Mysteries of Martian Ice Cap. Excerpt: PASADENA, Calif. -- Data from NASA's Mars Reconnaissance Orbiter (MRO) have helped scientists solve a pair of mysteries dating back four decades and provided new information about climate change on the Red Planet.
    …"SHARAD is giving us a beautifully detailed view of ice deposits, whether at the poles or buried in mid-latitudes, as they changed on Mars over the last few million years," said Rich Zurek, MRO project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
    ...One of the most distinctive features of the northern ice cap is Chasma Boreale, a canyon about as long as Earth's Grand Canyon but deeper and wider. Some scientists believe Chasma Boreale was created when volcanic heat melted the bottom of the ice sheet and triggered a catastrophic flood. Others suggest strong polar winds carved the canyon out of a dome of ice.
    …Data from Mars now points to both the canyon and spiral troughs being created and shaped primarily by wind. Rather than being cut into existing ice very recently, the features formed over millions of years as the ice sheet grew. By influencing wind patterns, the shape of underlying, older ice controlled where and how the features grew.
  • 2010 January 27. NASA gives up effort to free Mars rover. By David Pearlman, SF Chronicle. Excerpt: Scientists controlling the six-year journey of Spirit, the robot explorer stuck fast in a patch of sand on Mars, have given up efforts to free it.
    It will now serve as a research outpost standing alone on the red planet, and if it survives the deep freeze of the coming Martian winter, the once-mobile vehicle will try to help scientists solve a long-standing mystery about the planet's core: whether it's liquid like Earth's or solid all the way through.
    Spirit landed on Mars in January 2004 and traveled across nearly 5 miles of the planet's sandy surface and rocks. Along the way, it reported on evidence of past water that the chemistry of the rocks revealed. Ten months ago, one of its six wheels broke through a patch of crusty soil and the vehicle sank belly-deep into soft sand.
    Engineers have tried varied strategies to free the vehicle; they've commanded Spirit to spin its working wheels forward and backward - one of its wheels had failed in 2006, and another quit working in November. Every effort the scientists made to free Spirit failed.
    ...If Spirit makes it through winter, its mission will include studying the detailed chemistry of the sand within reach of the instruments on its robotic arm, monitoring the Martian atmosphere, and watching how the Martian wind moves soil particles as the wind direction changes.
    ...By watching over many months for tiny variations in the wobble of the planet as it spins on its axis, Squyres said, scientists will be able to determine whether or not Mars has a liquid core, or whether the planet is solid....
  • 2009 September 24. NASA RELEASE: 09-224. NASA SPACECRAFT SEES ICE ON MARS EXPOSED BY METEOR IMPACTS. Excerpt: PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter has revealed frozen water hiding just below the surface of mid-latitude Mars. The spacecraft's observations were obtained from orbit after meteorites excavated fresh craters on the Red Planet.
    Scientists controlling instruments on the orbiter found bright ice exposed at five Martian sites with new craters that range in depth from approximately half a meter to 2.5 meters (1.5 feet to 8 feet). The craters did not exist in earlier images of the same sites. Some of the craters show a thin layer of bright ice atop darker underlying material. The bright patches darkened in the weeks following initial observations, as the freshly exposed ice vaporized into the thin Martian atmosphere. One of the new craters had a bright patch of material large enough for one of the orbiter's instruments to confirm it is water-ice.
    The finds indicate water-ice occurs beneath Mars' surface halfway between the north pole and the equator, a lower latitude than expected in the Martian climate.
    "This ice is a relic of a more humid climate from perhaps just several thousand years ago," said Shane Byrne of the University of Arizona, Tucson....
  • 2009 May 21. RELEASE : 09-117. NASA Rover Sees Variable Environmental History at Martian Crater. Excerpt: PASADENA, Calif. -- One of NASA's two Mars rovers has recorded a compelling saga of environmental changes that occurred over billions of years at a Martian crater.
    The Mars rover, Opportunity, surveyed the rim and interior of Victoria Crater on the Red Planet from September 2006 through August 2008....
    The rover revealed the effects of wind and water. The data show water repeatedly came and left billions of years ago. Wind persisted much longer, heaping sand into dunes between ancient water episodes. These activities still shape the landscape today. At Victoria, steep cliffs and gentler alcoves alternate around the edge of a bowl about a half a mile in diameter. The scalloped edge and other features indicate the crater once was smaller than it is today, but wind erosion has widened it gradually.
    "What drew us to Victoria Crater is the thick cross-section of rock layers exposed there," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is the principal investigator for the science payloads on Opportunity and its twin rover Spirit. "The impact that excavated the crater millions of years ago provided a golden opportunity, and the durability of the rover enabled us to take advantage of it."...
  • 2008 November 20. RELEASE : 08-304. NASA Spacecraft Detects Buried Glaciers on Mars. Excerpt: PASADENA, Calif.-- NASA's Mars Reconnaissance Orbiter has revealed vast Martian glaciers of water ice under protective blankets of rocky debris at much lower latitudes than any ice previously identified on the Red Planet.
    ..."Altogether, these glaciers almost certainly represent the largest reservoir of water ice on Mars that is not in the polar caps," said John W. Holt of the University of Texas at Austin, who is lead author of the report. "Just one of the features we examined is three times larger than the city of Los Angeles and up to half a mile thick. And there are many more. In addition to their scientific value, they could be a source of water to support future exploration of Mars."
    Scientists have been puzzled by what are known as aprons -- gently sloping areas containing rocky deposits at the bases of taller geographical features -- since NASA's Viking orbiters first observed them on the Martian surface in the1970s. One theory has been that the aprons are flows of rocky debris lubricated by a small amount ice. Now, the shallow radar instrument on the Mars Reconnaissance Orbiter has provided scientists an answer to this Martian puzzle.
    "These results are the smoking gun pointing to the presence of large amounts of water ice at these latitudes," said Ali Safaeinili, a shallow radar instruments team member with NASA's Jet Propulsion Laboratory in Pasadena, Calif....
  • 2008 October 28. RELEASE : 08-273. NASA Orbiter Reveals Details of a Wetter Mars. Excerpt: WASHINGTON -- NASA's Mars Reconnaissance Orbiter has observed a new category of minerals spread across large regions of Mars. This discovery suggests that liquid water remained on the planet's surface a billion years later than scientists believed, and it played an important role in shaping the planet's surface and possibly hosting life.
    Researchers examining data from the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars have found evidence of hydrated silica, commonly known as opal. The hydrated, or water-containing, mineral deposits are telltale signs of where and when water was present on ancient Mars.
    "This is an exciting discovery because it extends the time range for liquid water on Mars, and the places where it might have supported life," said Scott Murchie, the spectrometer's principal investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "The identification of opaline silica tells us that water may have existed as recently as 2 billion years ago."
    ..."We see numerous outcrops of opal-like minerals, commonly in thin layers extending for very long distances around the rim of Valles Marineris and sometimes within the canyon system itself," said Ralph Milliken of NASA's Jet Propulsion Laboratory in Pasadena, Calif.
    ...The study reveals that the minerals, which also were recently found in Gusev Crater by NASA's Mars rover Spirit, are widespread and occur in relatively young terrains.
    ..."What's important is that the longer liquid water existed on Mars, the longer the window during which Mars may have supported life," says Milliken. "The opaline silica deposits would be good places to explore to assess the potential for habitability on Mars, especially in these younger terrains." ...
  • 2008 Sep 8. An Icy Discovery on Mars, but Where's the Water? By KENNETH CHANG, NY Times. Excerpt: After a much ballyhooed discovery two months ago of water ice in the northern plains of Mars, scientists are now perplexed by the water that NASA's Phoenix Mars lander has not found.
    ...Phoenix's weather station has also detected wisps of water vapor in the thin Martian air, and scientists expected that as the nighttime temperature plunged to minus-110 degrees Fahrenheit from minus-20 - and with it the amount of moisture that the Martian air can hold - minuscule specks of moisture would glom onto dust particles at the surface. The presence of water would show up in electrical measurements by a probe stuck into the soil. Except Mars has not cooperated.
    "We're seeing nothing," said Aaron Zent of the NASA Ames Research Center at Moffett Field, Calif., the lead scientist for Phoenix's thermal and electroconductivity probe. "Big fat nothing."
    Actually, the first measurement did yield the expected readings. "A lovely signal," Dr. Zent said. "But we never saw it again."
    Every subsequent measurement, taken at almost all hours of the day, indicated dry soil.
    ...The moisture in the air during the day has to go somewhere at night, and that somewhere seems almost certain to be the soil. "It has to," Dr. Zent said. "There's no other place for it to go. The soil is sucking it up at night. We certainly expect that we should be able to see some of this."
    ...The next step is for Phoenix to jam its electroconductivity probe deeper into the soil, closer to the ice layer. Maybe then, Phoenix will once again discover water.
  • 2008 Aug 14. PHOENIX MICROSCOPE TAKES FIRST IMAGE OF MARTIAN DUST PARTICLE. NASA's Phoenix Mars Lander has taken the first-ever image of a single particle of Mars' ubiquitous dust, using its atomic force microscope. The particle -- shown at higher magnification than anything ever seen from another world -- is a rounded particle about one micrometer, or one millionth of a meter, across. It is a speck of the dust that cloaks Mars. Such dust particles color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars' distinctive red soil.
  • 2008 July 31. RELEASE: 08-195. NASA SPACECRAFT CONFIRMS MARTIAN WATER, MISSION EXTENDED. Excerpt: TUCSON, Ariz. -- Laboratory tests aboard NASA's Phoenix Mars Lander have identified water in a soil sample. The lander's robotic arm delivered the sample Wednesday to an instrument that identifies vapors produced by the heating of samples.
    "We have water," said William Boynton of the University of Arizona, lead scientist for the Thermal and Evolved-Gas Analyzer, or TEGA. "We've seen evidence for this water ice before in observations by the Mars Odyssey orbiter and in disappearing chunks observed by Phoenix last month, but this is the first time Martian water has been touched and tasted."
    With enticing results so far and the spacecraft in good shape, NASA also announced operational funding for the mission will extend through Sept. 30. The original prime mission of three months ends in late August. The mission extension adds five weeks to the 90 days of the prime mission.
    ...The soil sample came from a trench approximately 2 inches deep. When the robotic arm first reached that depth, it hit a hard layer of frozen soil. Two attempts to deliver samples of icy soil on days when fresh material was exposed were foiled when the samples became stuck inside the scoop. Most of the material in Wednesday's sample had been exposed to the air for two days, letting some of the water in the sample vaporize away and making the soil easier to handle.
    "Mars is giving us some surprises," said Phoenix principal investigator Peter Smith of the University of Arizona. "We're excited because surprises are where discoveries come from. One surprise is how the soil is behaving. The ice-rich layers stick to the scoop when poised in the sun above the deck, different from what we expected from all the Mars simulation testing we've done. ...For more about Phoenix, visit:
  • 2008 July 16. NASA SPACECRAFT SHOWS DIVERSE, WET ENVIRONMENTS ON ANCIENT MARS. RELEASE : 08-177. Excerpt: Two studies based on data from NASA's Mars Reconnaissance Orbiter have revealed that the Red Planet once hosted vast lakes, flowing rivers and a variety of other wet environments that had the potential to support life. For more specific information on the two studies, visit:
  • 2008 May 15. NASA SATELLITE FINDS INTERIOR OF MARS IS COLDER. NASA RELEASE: 08-128. Excerpt: WASHINGTON -- New observations from NASA's Mars Reconnaissance Orbiter indicate that the crust and upper mantle of Mars are stiffer and colder than previously thought. The findings suggest any liquid water that might exist below the planet's surface and any possible organisms living in that water, would be located deeper than scientists had suspected. "We found that the rocky surface of Mars is not bending under the load of the north polar ice cap," said Roger Phillips of the Southwest Research Institute in Boulder, Colo.
    ..."The lithosphere of a planet is the rigid part. On Earth, the lithosphere is the part that breaks during an earthquake," said Suzanne Smrekar, deputy project scientist for Mars Reconnaissance Orbiter at JPL. "The ability of the radar to see through the ice cap and determine that there is no bending of the lithosphere gives us a good idea of present day temperatures inside Mars for the first time."
    ...The radar pictures also reveal four zones of finely spaced layers of ice and dust separated by thick layers of nearly pure ice. Scientists think this pattern of thick ice-free layers represents cycles of climate change on Mars on a time scale of roughly one million years. Such climate changes are caused by variations in the tilt of the planet's rotational axis and in the eccentricity of its orbit around the sun. The observations support the idea that the north polar ice cap is geologically active and relatively young, at about 4 million years.
  • 2008 Apr 25. Icy Active Mars. ...The prevailing thinking is that Mars is a planet whose active climate has been confined to the distant past. About 3.5 billion years ago, the Red Planet had extensive flowing water and then fell quiet - deadly quiet. It didn't seem the climate had changed much since. Now, in a research article that graces the May cover of Geology, scientists at Brown University think Mars' climate has been much more dynamic than previously believed. The findings could have important implications in determining whether or not Mars was ever a suitable habitat for life in the planet's past. After examining stunning high-resolution images taken last year by the Mars Reconnaissance Orbiter, the researchers have documented for the first time that ice packs at least 1 kilometer (0.6 miles) thick and perhaps 2.5 kilometers (1.6 miles) thick existed along Mars' mid-latitude belt as recently as 100 million years ago. In addition, the team believes other images tell them that glaciers flowed in localized areas in the last 10 to 100 million years - akin to the day before yesterday in Mars' geological timeline.
  • 2008 Mar 20. Mars is 'covered in table salt'. By Helen Briggs, Science reporter, BBC News. Excerpt: Mars appears to be covered in salt crystals from ancient dried-up lakes, new evidence suggests. A Nasa probe has found signs that the southern hemisphere is dusted with chloride mineral, perhaps "table salt". US scientists think the mineral formed when water evaporated from salty lakes or soil billions of years ago. The deposits, similar to salt-pans on Earth, are a good place to search for traces of past life preserved in salt, they report in the journal Science. The evidence comes from a camera on Mars Odyssey, which has been mapping the Red Planet since early 2002.
    ...Team member Professor Philip Christensen, of the School of Earth and Planetary Exploration at Arizona State University, Tempe, said ... "Two possible mechanisms would be the evaporation of a large body of water (like a salt lake on Earth), or capillary action in the soil that could draw salt-rich water toward the surface, where the water evaporates and the salt is left behind and accumulates. Either case is exciting because it implies a large amount of water near the surface."....

  • 2008 Mar 3. Avalanches on Mars. ...A NASA spacecraft in orbit around Mars has taken the first ever image of active avalanches near the Red Planet's north pole. ..."We were checking for springtime changes in the carbon-dioxide frost covering a northern dune field, and finding the avalanches was completely serendipitous," says JPL's Candice Hansen, deputy principal investigator for HiRISE. ..."We don't know what set off these landslides," says Patrick Russell of the University of Berne, Switzerland, a HiRISE team collaborator. "We plan to take more images of the site through the changing Martian seasons to see if this kind of avalanche happens all year or is restricted to early spring." ..."If blocks of ice broke loose and fell, we expect the water in them will be changing from solid to gas," Russell says. "We'll be watching to see if blocks and other debris shrink in size. What we learn could give us a better understanding of one part of the water cycle on Mars."
    The avalanche photo is one of approximately 2,400 HiRISE images released on March 3, 2008.
  • 2008 Feb 21. Research Explains Formation of Unique Martian Fans. By KENNETH CHANG , NY Times. To figure out an odd landscape feature on Mars, play in a big sandbox. Enlist some high school students, too.
    That's what some scientists at the Utrecht University in the Netherlands did, and they believe they now know how sediment deposits spilling out of the mouth of some water channels on Mars were shaped in a series of terraces that look like terraced rice paddies.
    But no similar natural formations have been seen in river deltas on Earth. Usually river sediments spill out in a smooth, sloping fan like the Mississippi delta.
    Planetary geologists have been speculating about the terraced fans since they were first spotted by NASA's Mars Global Surveyor eight years ago. About 10 stepped fans have been identified, most at the base of a steep slope emptying into a basin like an impact crater. (Most of the 200 sediment fans seen on Mars do not have the stepped structure. Another mystery is why many of the river channels seem to have no sediment deposit at all.)
    Some scientists suggested the terraced fans were the result of repeated shore erosion as a lake in the basin dried up. Others thought repeated landslides might have formed the steps.
    The sandbox experiment, reported in Thursday's issue of the journal Nature, supports a third notion. The terraces form by the interaction of the sediment flow with the water's edge, which is rising as the basin fills. "Where that's happening, you're getting a little lip," said Erin R. Kraal, the lead author of the Nature paper. Pulses of flow and sediment produced multiple terraces.
    "They're just stacking one atop the other," she said. While a postdoctoral researcher at Utrecht, Dr. Kraal became intrigued by the terraced fans.... Utrecht has a set-up known as Eurotank, essentially a 16- by 40-foot sandbox for studying sedimentary dynamics.
    High school students visiting the laboratory as part of an educational project saw the Mars pictures on the laboratory walls and were interested in helping on an experiment, which eventually turned into a short educational movie about the Martian fans.
    The students dug a crater in the sandbox and shaped a water channel. Then they sent water down the channel - and the result was a terraced fan, just as on Mars.
    "We didn't expect it to be so successful the first time," said Dr. Kraal, now a research scientist at Virginia Polytechnic Institute and State University. "We were really surprised they formed so quickly and so easily."....
  • 21 September 2007 NASA RELEASE: 07-207 - NASA ORBITER FINDS POSSIBLE CAVE SKYLIGHTS ON MARS. Excerpt: PASADENA, Calif. -- NASA's Mars Odyssey spacecraft has discovered entrances to seven possible caves on the slopes of a Martian volcano. The find is fueling interest in potential underground habitats and sparking searches for caverns elsewhere on the Red Planet.
    ...Evidence that the holes may be openings to cavernous spaces comes from the temperature differences detected from infrared images taken in the afternoon and in the pre-dawn morning.
    ..."Whether these are just deep vertical shafts or openings into spacious caverns, they are entries to the subsurface of Mars," said co-author Tim Titus of the U.S. Geological Survey in Flagstaff. "Somewhere on Mars, caves might provide a protected niche for past or current life, or shelter for humans in the future."
    ...For additional information about Mars Odyssey and the new findings, visit:
  • 9 July 2007. NASA Readies Mars Lander for August Launch to Icy Site
    NASA RELEASE: 07-148. WASHINGTON - NASA's next Mars mission will look beneath a frigid arctic landscape for conditions favorable to past or present life. ...NASA's Phoenix Mars Lander will claw down into the icy soil of the Red Planet's northern plains. The robot will investigate whether frozen water near the Martian surface might periodically melt enough to sustain a livable environment for microbes. To accomplish that and other key goals, Phoenix will carry a set of advanced research tools never before used on Mars. ..."Our 'follow the water' strategy for exploring Mars has yielded a string of dramatic discoveries in recent years about the history of water on a planet where similarities with Earth were much greater in the past than they are today," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters, Washington. "Phoenix will complement our strategic exploration of Mars by being our first attempt to actually touch and analyze Martian water -- water in the form of buried ice."
    NASA's Mars Odyssey orbiter found evidence in 2002 to support theories that large areas of Mars, including the arctic plains, have water ice within an arm's reach of the surface.
    ....Additional information on the Phoenix mission is available online at:
  • February and March 2007. NSTA WEB SEMINARS ON MARS. NASA JPL and NSTA series of free Web seminars for 5-12 science educators on the topic of Mars Exploration. Allow several minutes to download/start.
  • 29 January 2007. Did Martian Meteorites Come From These Sources? By Linda M. V. Martel, Hawai'i Institute of Geophysics and Planetology. Excerpt: Large rayed craters on Mars, not immediately obvious in visible light, have been identified in thermal infrared data obtained from the Thermal Emission Imaging System (THEMIS) onboard Mars Odyssey. ... rays consist of numerous chains of secondary craters, their overlapping ejecta, and possibly primary ejecta from the source crater. ... physical details of the rayed craters and the target surfaces combined with current models of Martian meteorite delivery ... lead Tornabene and coauthors to conclude that these large rayed craters are plausible source regions for Martian meteorites.
  • 25 January 2007. Mars' Missing Air Might Just be Hiding. By Ker Than, Excerpt: Rather than having had its air knocked out into space, Mars might just be holding its breath. New findings suggests the missing atmosphere of Mars might be locked up in hidden reservoirs on the planet, rather than having been chafed away by billions of years' worth of solar winds as previously thought. Combining two years of observations by the European Space Agency's Mars Express spacecraft, researchers determined that Mars is currently losing only about 20 grams of air per second into space. Extrapolating this measurement back over 3.5 billion years, they estimate that only a small fraction, 0.2 to 4 millibars, of carbon dioxide and a few centimeters of water could have been lost to solar winds during that timeframe.....
  • 6 December, 2006. NASA Images Suggest Water still Flows in Brief Spurts ON Mars - NASA RELEASE: 06-362. WASHINGTON - NASA photographs have revealed bright new deposits seen in two gullies on Mars that suggest water carried sediment through them sometime during the past seven years. "These observations give the strongest evidence to date that water still flows occasionally on the surface of Mars," said Michael Meyer, lead scientist for NASA's Mars Exploration Program, Washington. For more information about NASA's Mars missions, visit:
  • 28 July 2005 - Mars Express images of a patch of water ice sitting on the floor of an unnamed crater near the Martian north pole.White patch is present all year round, as the temperature and pressure conditions do not favour the sublimation of water ice. It cannot be frozen carbon dioxide since carbon dioxide ice had already disappeared from the north polar cap at the time the image was taken (late summer in the Martian northern hemisphere).
  • 27 December 2005 Magma and Water on Mars. By G. Jeffrey Taylor --- Martian meteorites tell us part of the fascinating story about when volcanoes erupted and water flowed. Lars Borg (University of New Mexico) and Michael Drake (University of Arizona) synthesized available age data for Martian meteorites. Cosmochemists have determined when a variety of Martian igneous rocks crystallized and when their original minerals were altered by interaction with water. Igneous events occurred soon after the planet formed 4500 million years ago and continued to about 174 million years ago. Water affected the planet beginning within 100 million years of solar system formation and continued to less than 170 million years ago, perhaps to now. These observations tie in reasonably well with what we know from photogeologic studies of Mars, but we need more quantitative age determinations, implying sophisticated in situ age measurements and sample return missions. Hawai'i Institute of Geophysics and Planetology.
  • 28 July2005 Water ice in crater at Martian north pole - Images taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft show a patch of water ice sitting on the floor of an unnamed crater near the Martian north pole.
  • 6 April 2005. NASA RELEASE: 05-091. Durable Mars Rovers Sent into Third Overtime Period. NASA has approved up to 18 more months of operations for Spirit and Opportunity, the twin Mars rovers that have already surprised engineers and scientists by continuing active exploration for more than 14 months. "The rovers have proven their value with major discoveries about ancient watery environments on Mars that might have harbored life," said Dr. Ghassem Asrar, deputy associate administrator for NASA's Science Mission Directorate. "We are extending their mission through September 2006 to take advantage of having such capable resources still healthy and in excellent position to continue their adventures." The rovers have already completed 11 months of extensions on top of their successful three-month prime missions. "We now have to make long-term plans for the vehicles because they may be around for quite a while," said Jim Erickson, rover project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. See also
  • 2 March 2005 Mars Exploration Rover sites zoom-in movies - From Nick Strobel of Bakersfield College: Two Flash movies that zoom to the very highest resolution image of the Mars Exploration Rovers Spirit and Opportunity from Mars orbit (Mars Global Surveyor) , from THEMIS images and MOC narrow-angle images of the area around Opportunity's location (Meridiani Planum). Nick created these Flash movies for his astronomy class lecture. Still image source material:

    For Spirit Zoom movie:

    For Opportunity Zoom movie:

  • 21 February, 2005, Mars pictures reveal frozen sea. BBC News. The find has implications for life on Mars. A huge, frozen sea lies just below the surface of Mars, a team of European scientists has announced. Their assessment is based on pictures of the planet's near-equatorial Elysium region that show plated and rutted features across an area 800 by 900km. The team think a catastrophic event flooded the landscape five million years ago and then froze out.... Large reserves of water-ice are known to be held at the poles on Mars but if this discovery is confirmed by follow-up observations, it would be a first for a region at such a low latitude. ..."It's been predicted for a long time that you should find water close to the surface of Mars near the equator," Jan-Peter Muller, from University College London, UK, said.... Finding exposed ice at the equator would be unlikely. Very low pressures on the planet would lead to sublimation - the ice would erode over time straight to water vapour. But the research group, led by John Murray, from the Open University, UK, tells Nature that a crust of dust and volcanic ash, perhaps just a few centimetres thick, has prevented this happening. "The story runs that water flowed in some kind of massive catastrophic event; pack ice formed on top of that water and broke up, and then the whole thing froze rigid," explains Professor Muller. "Large amounts of dust then fell over that area. The dust fell through the water and on top of the pack ice, which explains why the pack ice is a different hue to the area around it."
  • 2 December 2004. NASA Release: 04-385. Reports Detail Rover Discoveries of Wet Martian History. The most dramatic findings so far from NASA's twin Mars rovers -- telltale evidence for a wet and possibly habitable environment in the arid planet's past -- passed rigorous scientific scrutiny for publication in a major research journal.
  • 23 November 2004. Methane in Martian Air Suggests Life Beneath the Surface. NY Times. By KENNETH CHANG. A third team of scientists has now reported a seemingly simple discovery on Mars: its atmosphere contains methane. But that finding has potentially profound implications, including the possibility of present-day microbes living on Mars.
  • 21 September 2004 Methane on Mars causes controversy. news service, Maggie McKee. Methane and water vapour are concentrated in the same regions of the Martian atmosphere, say scientists studying data from Europe's Mars Express orbiter. They say the link may point to a common source - possibly life - but others remain sceptical about the detection. In March, scientists using the Planetary Fourier Spectrometer (PFS) on Mars Express announced they had found methane in the atmosphere at a level of just 10.5 parts per billion. Two other groups say they have also detected the gas with telescopes in Chile and Hawaii. Ultraviolet sunlight takes about 300 years to destroy atmospheric methane. These detections suggest the gas is being replenished on Mars in the same way it is on Earth - by processes such as geothermal heating or by life forms, such as bacteria.
  • 18 August 2004. Bedrock in Mars' Gusev Crater Hints at Watery Past. Now that NASA's Mars Exploration Rover Spirit is finally examining bedrock in the "Columbia Hills," it is finding evidence that water thoroughly altered some rocks in Mars' Gusev Crater. Spirit and its twin, Opportunity, completed successful three-month primary missions on Mars in April and are returning bonus results during extended missions. They remain in good health though beginning to show signs of wear.
  • 6 July 2004 Detailed analyses of Martian meteorites reveal that the planet's interior preserves distinctive regions that formed 4.5 billion years ago. Full story and a PDF link at:
  • 9 June 2004 New York Times: Rover Unearths More Evidence of Water on Mars, Scientists Say. By JOHN SCHWARTZ. Residue of sulfur and magnesium in a trench in concentrations that suggest the minerals are combined as magnesium sulfate, or Epsom salt, may mean that water percolated through the soil.
  • 6 May 2004. Mars and the Teachable Moment. By Edna DeVore, Director of Education and Public Outreach. The face on Mars is a teachable moment. Turn your students into scientists. Present the evidence for the students to consider. There is the Viking photograph, taken in 1976 and the Mars Global Surveyor (MGS) photographs taken about 25 years later. Ask the students what they see in the 1976 photograph--like everyone else, they will see a face.... Move forward a couple of decades. ... We have new, higher resolution photographs of the same mesa taken by MGS and posted to the web by Malin Space Science Systems, the designers and builders of the camera onboard MGS. ...Send your students there for the evidence.
  • 20 April 2004. NASA RELEASE: 04-131 THE CASE OF THE ELECTRIC MARTIAN DUST DEVILS -- Scientists have found clues dust devils on Mars might have high-voltage electric fields, based on observations of their terrestrial counterpart. This research supports the vision for space exploration by helping to understand challenges the martian environment presents to explorers, both robotic and, eventually, human.
  • 23 March 2004, NASA RELEASE: 04-100. STANDING BODY OF WATER LEFT ITS MARK IN MARS ROCKS. NASA's Opportunity rover has demonstrated some rocks on Mars probably formed as deposits at the bottom of a body of gently flowing saltwater. "We think Opportunity is parked on what was once the shoreline of a salty sea on Mars," said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the science payload on Opportunity and its twin Mars Exploration Rover, Spirit.
  • 22 March 2004 NASA's M2K4 Web site's interactive (flash) program to drive NASA's Mars Rovers, Spirit and Opportunity, across the red planet.
  • 10 March 2004. Phil Plait discusses Richard Hoaglands "Face-on-Mars."
  • Jan 2004 Mars Exploration Rovers landed -- -- Briefings at
  • Mars at Its All-Time Finest, By Daniel M. Troiani

  • Increase in apparent size of Mars in 2003.
  • 7 August 2003. Mars is Melting (NASA Science News) The south polar ice cap of Mars is receding, revealing frosty mountains, rifts and curious dark spots.
  • 24 July 2003. Los Alamos releases new maps of Mars water. LOS ALAMOS, N.M. -- "Breathtaking" new maps of likely sites of water on Mars showcase their association with geologic features such as Vallis Marineris, the largest canyon in the solar system. The maps detail the distribution of water-equivalent hydrogen as revealed by Los Alamos National Laboratory-developed instruments aboard NASA's Mars Odyssey spacecraft.
  • Mars Exploration Rover -- Launch: May/July 2003; Landing: January 2004
  • 26 June 2003. JPL RELEASE: 03-216. NASA'S ODYSSEY ORBITER WATCHES A FROSTY MARS. NASA's Mars Odyssey spacecraft is revealing new details about the intriguing, dynamic character of the frozen layers now known to dominate the high northern latitudes of Mars. The implications have a bearing on science strategies for future missions in the search of habitats. See...Full article.
  • 14 January 2003. Potential landing sites for Mars Exploration Rovers are relatively near landing sites for Viking 1 and 2, and Mars Pathfinder. The data is from Mars Global Surveyor.
  • 5 December 2002, Exposed Water Ice Discovered Near the South Pole of Mars USGS Press Release -- Surface water in the form of ice exposed near the edge of Mars's southern perennial polar cap has been discovered for the first time, according to U.S. Geological Survey (USGS) research released today in the journal Science. There is evidence that the surface water ice in this region may be widespread - from a half-mile to six miles around the entire southern polar ice cap. For more information on thermal observations of the Mars polar region, please visit
  • 3 December 2002. NEW CU-NASA RESEARCH BELIES PREVIOUS IDEA THAT MARS WAS ONCE WARM, WET PLANET. A new study led by University of Colorado at Boulder researchers indicates Mars has been primarily a cold, dry planet following its formation some 4 billion years ago, making the possibility of the evolution of life there challenging at best. Press Release from University of Colorado at Boulder.
  • 30 October 2002. Mars opposition of 2003--Note from Dome-L, Jean Meeus's book "Astronomical Tables of the Sun, Moon, & Planets" does have a listing of Mars oppositions from A.D. 0-3000. In a rapid glance through it, there was no earlier opposition closer than the 2003 one. However, the next closer one occurs on Aug 28. 2287, when Mars is 55.69 million kilometers away and the closest one over that 3000 year interval occurs on Sep. 8, 2729, when Mars is 55.65 million kilometers away. -- Lee Shapiro ( National Radio Astronomy Observatory
  • 28 May 2002 --RELEASE: 02-99 -- ODYSSEY FINDS WATER ICE IN ABUNDANCE UNDER MARS' SURFACE. and Using instruments on NASA's 2001 Mars Odyssey spacecraft, surprised scientists have found enormous quantities of buried treasure lying just under the surface of Mars-enough water ice to fill Lake Michigan twice over. And that may just be the tip of the iceberg. "This is really amazing. This is the best direct evidence we have of subsurface water ice on Mars. We were hopeful that we could find evidence of ice, but what we have found is much more ice than we ever expected," said William Boynton, principal investigator for Odyssey's gamma ray spectrometer suite at the University of Arizona, Tucson. Scientists used Odyssey's gamma ray spectrometer instrument suite to detect hydrogen, which indicated the presence of water ice in the upper meter (three feet) of soil in a large region surrounding the planet's south pole. "It may be better to characterize this layer as dirty ice rather than as dirt containing ice," added Boynton. The amount of hydrogen detected indicates 20 to 50 percent ice by mass in the lower layer. Because rock has a greater density than ice, this amount is more than 50 percent water ice by volume. This means that if one heated a full bucket of this ice-rich polar soil it would result in more than half a bucket of water.
  • March 2002, A Whiff of Vanished Martian Seas, By J. KELLY BEATTY, Sky & Telescopemagazine, p. 18. FUTURE ASTRONAUTS ROAMING THE SURFACE OF MARS WILL BE hard-pressed to find sources of water, but the red planet was not always as arid as it is now. From minuscule gullies to giant floodplains, the face of Mars bears mute witness to eras when water must have gushed across its surface at least briefly.
  • March 2002. Martian Gully Mystery Solved? By DAVID TYTELL, Sky & Telescope magazine, p. 19. PLANETARY SCIENTISTS MAY BE (JOSE TO EXPLAINING HOW THE enigmatic little Martian gullies formed relatively recently. According to research published in Science Express by François Costard and François Forget (University of Paris) and others, changes in Mars's obliquity (polar tilt) can easily lead to the melting of shallow subsurface ice in just the right places.
  • March 2002, Mars's Active Snow and Ice. Sky & Telescope, p. 18. IMAGES RETURNED BY THE MARS GLOBAL SURVEYOR (MGS) orbiter suggest that the Martian polar caps and perhaps Mars's entire atmosphere and climate may be surprisingly unstable on a time scale of just a few centuries or thousands of years. Astronomers analyzed images of the south polar region and found ice cliffs retreating surprisingly fast. The speed of their shrinkage, given the temperatures and amounts of sunlight in the region, confirms that the material is frozen carbon dioxide (CO2). Water ice could not sublimate (evaporate directly from solid to gas) nearly so fast.
  • 5 May 2002. Global Surveyor images of Martian duststorms of 2001. or see alternate image site.
  • 27 March 2002 Odyssey Serves Up Canyon Images. Now in its final orbit, Mars Odyssey is getting to work searching for water on the surface of the planet. The most recent set of images returned are of a network of channels taken by the Thermal Emission Imaging System (THEMIS). The Nirgal Vallis is a channel 500 km long and 6 km wide at this point - astronomers believe that gullies on the side of the channel were formed when water erupted to the surface.
  • 11 February 2002 New Images from Mars Global Surveyor Released -- -- NASA's Mars Global Surveyor began its second year of extended operations at the beginning of February, and recently delivered a whole new batch of images of the Red Planet. These images were taken over course of the spacecraft's first year of extended operations.
  • 19 December 2001 -- ALL-TERRAIN ROVERS MAY SCALE MARS' CLIFFS -- -- NASA researchers are developing new prototype robots that can drive up steep hills and descend almost-vertical cliffs. Recent Mars Global Surveyor images suggest water outflows near cliff edges and the possibility of rich water-borne mineral deposits that extend all the way to the cliff base. Working alone or as a team, these autonomous robotic explorers may go where no rover has gone before -- the cliffs of Mars. RELEASE: 01-251
  • 6 December 2001 -- Mars Global Surveyor -- Mars Orbiter Camera (MOC) Observes Changes in the South Polar Cap: Evidence for Recent Climate Change on Mars, Martian South Polar Pits in Layer of Frozen Carbon Dioxide Martian Ice Caps are Eroding --New photos taken by the Mars Global Surveyor are tracking the changes to the Martian polar ice caps, and from what scientists can tell, they're shrinking. If true, this would indicate the Mars is warming up, and it's atmosphere is becoming more dense. In fact, if the erosion of the carbon dioxide ice continues, some scientists predict that Mars could become significantly warmer in just a few thousand years. Other scientists urge caution, though, pointing out that we don't have enough data to confirm climate change. MGS MOC Release No. MOC2-297
  • 6 December 2001 -- NASA'S GLOBAL SURVEYOR SEES POSSIBLE CLIMATE CHANGE ON MARS. The planet Mars we know today is a cold, dry, desert world, but suppose the martian climate is changing even now, year to year and decade to decade? New observations by NASA's Mars Global Surveyor spacecraft are expanding understanding of the martian climate and may indicate the climate is changing significantly even today. RELEASE: 01-240
  • 29 November 2001. MARS WAS ONCE ALL WET. Although covered by frozen deserts today, Mars could have been born with more water in proportion to its mass than the Earth, according to new observations from NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) spacecraft.
  • 9 November 2001. NASA SELECTS 10 INVESTIGATIONS FOR 2005 MARS RECONNAISSANCE ORBITER-- NASA today announced the selection of 10 scientific investigations as part of the 2005 Mars Reconnaissance Orbiter (MRO) mission. The 2005 MRO will carry six primary instruments that will greatly enhance the search for evidence of water, take images of objects about the size of a beach ball, and search for future landing sites on the Martian surface. RELEASE: 01-220
  • 29 October 2001. NASA BULLDOZER ROVERS COULD GET THE SCOOP ON MARS --Tiny bulldozer rovers may some day dish up the dirt and pack it in on Mars. The scoop-and-dump design of a prototype bulldozer rover being developed by NASA engineers mimics that of a bulldozer and dump truck. RELEASE: 01-208
  • 11 October 2001 SCIENTISTS TRACK "PERFECT STORM" ON MARS A pair of eagle-eyed NASA spacecraft -- the Mars Global Surveyor (MGS) and Hubble Space Telescope -- are giving amazed scientists a ringside seat to the biggest global dust storm seen on Mars in several decades. RELEASE: 01-193
  • 5 July 2001 Hubble Captures Best View of Mars Ever Obtained From Earth
  • 9 May 2001. New image of a human-like face on Mars
  • 1 May 2001, Space Weather on Mars [Science@NASA]
  • 19 March 2001-- NASA's latest mission to Mars, 2001 Mars Odyssey, an orbiter scheduled for launch on April 7th, 2001 will seek out underground water-ice and explore space weather around the Red Planet.
  • 4 December 2000 -- Evidence of Martian Land of Lakes Discovered.
  • 28 September 2000 -- 2001 MARS ODYSSEY NASA Press release
  • 6 June 2000 Mars Global Surveyor -- Mars Orbiter Camera Images Suggest Recent Sources of Liquid Water on Mars-- Gullies seen on martian cliffs and crater walls in a small number of high-resolution images from the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) suggest that liquid water has seeped onto the surface in the geologically recent past.
  • 17 March 2000 -- Martian Dust Devil Caught
  • 10 March 2000 -- More Surprises on Mars (Sky and Telescope) -- 1-kilometer-square field of surface pits (each about 2 meters deep) that give the region of the northern polar cap a spongelike appearance.
  • 5 November 1999. Shadow of Phobos on Mars
  • 19 May 1999 -- Hubble Views Colossal Polar Cyclone on Mars (STScI Press Release)
  • 25 March 1999 -- Oxygen Generation on Mars -- NASA EXPERIMENT LAYS GROUNDWORK FOR 'LIVING OFF THE LAND' ON MARS (NASA Press Release)
  • 22 February 1999 -- Martian Colors Provide Clues about Martian Water (STScI Press Release)

Dust Devil movies (MER Spirit)

View from orbit:

Other multimedia files at

MARS EXPLORATION: MARS FOR EDUCATORS, NASA, 11 classroom activities focusing on the Red Planet

A towering dust devil, casts a serpentine shadow over the Martian surface in this image acquired by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.
A towering dust devil, casts a serpentine shadow over the Martian surface in this image acquired by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech/Univ. of Arizona.

Online Book:

The Planet Mars--A History of Observation and Discovery,
by William Sheehan, 1996, University of Arizona Press.
-- Chapter 5: 1877



Hard Copy Articles About Mars

  • Achenbach, Joel, Captured by Aliens, Astronomy Magazine, July 2000, pp. 42-47. ...efforts to conquer space.
  • Bell, Jim,Mars Pathfinder: Better Science?, Sky & Telescope Magazine, July 1998, p. 36.
  • Carr, Michael, The Proof Is In: Ancient Water On Mars. Planetary Report, May/June 2004. The latest findings by the rover Opportunity on the Meridiani Planum ahve confirmed the presence on Mars of standing bodies of water at some time in the past.
  • Dobbins, Thomas, and William Sheehan, Beyond the Dawes Limit: Observing Saturn's Ring Divisions, Sky & Telescope magazine, Nov 2000, p. 117. Starts with a discussion of Lowell's observations of Mars and that critics of Lowell argued that the Dawes limit precluded the possibility that Lowell could actually see the exceedingly fine lines that he concluded were canals on Mars. This article refutes those critics: resolution for detected two point sources is considerably different from that required to detect lines. "Harvard astronomer, William H. Pickering, found that he could detect a human hair at a distance of nearly a quarter mile, when its apparent width was reduced to only 0.03 arcsecond--1/14 the Dawes limit..."
  • Dobbins, Thomas A, and Sheehan, William, The Canals of Mars Revisited, Sky and Telescope Magazine, March 2004, p. 114. Recent digital images shed new light on one of visual planetary observing's most enduring mysteries.
  • Dobbins, Thomas, and William Sheehan, The Martian-Flares Mystery, Sky & Telescope magazine, May 2001, p. 115. Describes bright flares that have been observed on Mars dating back to 1951. Explanations range from natural reflections of sunlight from Martian seas or ice to activities of Martian inhabitants. Current thought is that the flares are "directed reflection of sunlight from clouds of aligned ice crystals floating in the Martian atmosphere."
  • DiGregorio, Barry, Life on Mars? 27 Years of Questions. Sky and Telescope Magazine, Feb 2004. p. 40.
  • Graham, Rex, Missing the Mark, Astronomy Magazine, July 2000, pp 48-53. "Several failed missions to Mars have forced NASA into a sobering reality check."
  • Hartmann, William K., Red Planet Renaissance, Astronomy Magazine, July 2000, pp. 35-41. "Recent discoveries paint Mars as an active planet with erupting volcanoes and underground rivers..."
  • Hoffman, Nick, White Mars--The Story of the Red Planet Without Water, Mercury Magazine (ASP), Jan-Feb, 2001 -- arguments for why the plans to search for water on Mars may be ill-founded.
  • Malin, Mike, Mars Geology Grows More Intriguing, Astronomy Magazine, March 2001 p. 20. Mike Malin and Ken Edgett of Malin Space Science Systems in San Diego, ..., found what appear to be thick masses of stratified sedimentary rock.
  • Miller, Ryder W., Reflections on the 100-Year Anniversary of The War of the Worlds: A Frontier and Literary History of Mars, Mercury Magazine, May-June, 1998 p. 13.
  • Naeye, Robert, Red-Letter Days, Sky & Telescope Magazine, May 2004, pp.44-48.
  • Parker, Semantha, The Triumphant Turnaround of Mars Global Surveyor, Sky & Telescope Magazine, August 1998, p. 42.
  • Tytell, David, Martian Mudflows, Sky and Telescope Magazine, Sept. 2000, p. 56, Sky Publishing.
  • Zimmerman, Robert, Launching a Caravan to Mars, Astronomy Magazine, Dec 2001, p. 40.

Books About Mars


[Note from Dr. Standish:]

...with the alignments [such as Earth oppositions], it doesn't take much accuracy to compute those, especially at any reasonable precision. The accuracy for spacecraft navigation is another matter; it tests the full extent of our abilities.

For the close approaches of Mars to earth, enclosed is a list of the 20 closest, covering 3000 BC to 3000 AD. I've listed 8 significant figures, but not all of them can be trusted, especially when projected far away from the present era: the motions are impossible to predict exactly, due to the perturbations of many asteroids whose masses are not perfectly known.

In the table, you can see that there is no approach listed that was closer than the upcoming approach in 2003. I'm guessing that it has been 100,000 years or so since one was closer. I can't really say without a bit of work, since our integrated ephemerides go back only to 3000 BC.

Myles Standish
* Dr E Myles Standish; JPL 301-150; Pasadena, CA 91109 *
* TEL: 818-354-3959 FAX: 818-393-6388 *
* Internet: [] *

AU km ET

0.37200418 55651033. 2729 SEP 08 04:50:40
0.37200785 55651582. 2650 SEP 03 18:00:36
0.37217270 55676243. 2934 SEP 05 03:05:19
0.37225400 55688405. 2287 AUG 28 22:26:30
0.37230224 55695623. 2808 SEP 11 15:38:05
0.37238224 55707590. 2571 AUG 30 06:21:32
0.37238878 55708568. 2366 SEP 02 08:06:43
0.37271925 55758006. 2003 AUG 27 09:52:17
0.37279352 55769117. 2208 AUG 24 09:01:12
0.37284581 55776939. 1924 AUG 22 23:49:58
0.37292055 55788120. 2887 SEP 16 00:21:59
0.37296343 55794535. 2445 SEP 05 16:44:56
0.37302110 55803163. 1845 AUG 18 11:37:30
0.37305741 55808594. 1482 AUG 03 12:14:47
0.37310445 55815632. 2855 AUG 31 18:14:59
0.37321735 55832521. 2492 AUG 24 19:26:41
0.37325251 55837780. 1561 AUG 07 00:12:01
0.37326031 55838948. 1766 AUG 13 22:57:16
0.37327582 55841268. 2129 AUG 19 21:51:46
0.37339761 55859488. 1119 JUL 31 14:29:16

The closest BC approach is 37th on the list:

AU km ET
0.3742246524 55983211.153 -0049 JUL 18 10:09:10



Mars images June 2001.

Mars through filters