Check out this magnificent collection of high-resolution images of at the University of Arizona Lunar & Planetary Laboratory. Almost birds-eye views of Mars' fascinating terrain, including the mysterious polar caps.
New maping measurements of Mars' south polar region by a joint NASA-Italian Space Agency instrument on the European Space Agency's Express spacecraft indicate extensive frozen water. The polar region contains enough frozen water to cover the whole planet in a liquid layer approximately 11 meters (36 feet) deep.
The Express orbiter's radar instrument has made more than 300 virtual slices through layered deposits covering the pole to map the ice. The radar sees through icy layers to the lower boundary, which is as deep as 3.7 kilometers (2.3 miles) below the surface.
For years, NASA's and the ESA's mantra for discovering life on is "follow the Water." Scientists who are hunting for life on - past or present - are expanding their search to include possible sources of food and energy, as well as water, that could nourish microorganisms on the Red Planet.
But the concept now is considered too narrow. The search for water goes on, but it's not the only target.
NASA's rovers, Spirit and Opportunity, along with U.S. and European orbiting spacecraft have detected evidence that was warm and wet billions of years ago, with rivers, lakes and perhaps a large ocean. That water has evaporated or sunk underground, occasionally bursting to the surface to carve fresh gullies in canyon walls.
Scientists say the search must extend below the planet's dry, frozen crust to look for buried supplies of water, food and energy where microbes might be living.
One potential Martian food is methane - natural gas - a simple compound of hydrogen and carbon. Traces of methane were detected last year in the planet's thin atmosphere, apparently leaking out of pockets of gas below the surface. Living creatures are a potential source of the methane detected in the atmosphere. If found, such organisms would be similar to colonies of microbes called methanogens, which feed on methane below the ocean floor on Earth.
Mars' interior retained heat, a form of energy, from the time of its formation 4.5 billion years ago. Radioactive rocks also emit a steady stream of energetic particles. also is loaded with iron, which combines with oxygen to give the planet its distinctive rust color.
Since the Viking missions of the 1970s, planetary scientists have changed their perception of water on several times,We are re-writing the history of Mars," says Gerhard Neukum, Freie Universitaet Berlin, Germany, and the Principal Investigator on Express’s High Resolution Stereo Camera (HRSC). "The big picture of a warm wet is not completely correct. Any warm wet period lasted only a few hundred million years. By four thousand million years ago, it was over," he adds.
Three instruments on the European Space Agency's Express have been at the centre of this revolution in thought. Since July 2005, the Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) has probed beneath the surface of to depths of thousands of metres.
The scientists detected abundant water ice (map above)in the Martian polar regions and also received a surprise from some of the very first results that MARSIS returned. When the radar passed over the mid northern latitudes of Chryse Planitia, the signals showed a buried impact crater, below the surface. Inside this impact structure was a thick layer of possibly water-ice-rich material. "We are finding reservoirs of ice that have never been seen before," says Plaut, "But we are still puzzling out when and where the water on was liquid."
is showing scientists that it has an older, craggier face buried beneath its surface from probes by the Express MARSIS, the first sub-surface sounding radar used to explore a planet provide important new clues about the still mysterious geological history of Mars. Observations by MARSIS' "x-ray vision" strongly suggest that ancient impact craters lie buried beneath much of the smooth, low plains of the northern hemisphere of Mars. Image left shows subsurface echoes from Chryse Planitia plains.
Posted by Casey Kazan.
Google teamed with NASA's Ames Research Center in December to produce high-resolution 3D maps of and the Moon in the same detail as Google Earth. Users will experience a virtual flight over the surface of the Moon or through the canyons of Mars.The collaboration will also seek to make Nasa data available on the internet, including live weather maps and forecasts, plus real-time tracking of the International Space Station and shuttle. Google will also assist Nasa in managing the vast amounts of information held across the agency’s network of computers. Posted by Jason McManus.
The frozen ocean was captured by cameras aboard the European Space Agency's Express probe, which revealed an expanse of pack ice just north of the Martian equator, in Elysium, a region strewn with dormant volcanoes.
Dust kicked up by violent storms appears to have settled on the icy surface, outlining fragmented ice rafts covering an area as large as the North Sea. The water is believed to have seeped up from fissures several kilometres beneath the surface, perhaps carrying ancient microbes with it, before freezing some 5 million years ago.
Elsewhere, The New Scientist has reported that is losing little water to space, according to new research, and that much of its ancient abundance may still be hidden beneath the surface.
Dried up riverbeds and other evidence imply that once had enough water to fill a global ocean more than 600 metres deep, together with a thick atmosphere of carbon dioxide that kept the planet warm enough for the water to be liquid. But the planet is now very dry and has a thin atmosphere.The European Space Agency's Express spacecraft has revealed that the rate of water loss from solar winds is much lower that previously estimated. Its measurements suggest the whole planet loses only about 20 grams per second of oxygen and CO2 to space. Either some other process removed the water and CO2 or they are still present and hidden somewhere on Mars, probably underground in huge reserviors.
Don't miss Peter Ward's third lecture, The Undesigned Universe in this Princeton Online series on astrobiology, where he argues for the possibility that DNA-bearing, carbon-based life is not the only form of life that may have evolved on earth. Ward, professor of astrobiology at the University of Washington and author of Life as We Know It -NASA Search for Alien Life, redraws the evolutionary tree to include RNA life, and conceivably many thousands or millions of other non-DNA-bearing lifeforms, which may have competed with, and lost out to, DNA-bearing life. He also explores the probability that we are in fact not a native Earth species but Martians who have evolved from earlier lifeforms to live on this planet. The lectures can be downloaded as audio or video.
In a recent issue of Seed Online, David Grinspoon, author of Lonely Planets -The Natural Philosophy of Alien Life and principal scientist at Boulder's Southwest Research Institute, notes that on February 28, 2007, for the first time, human technology will be operating on five planets (including Earth). The New Horizons spacecraft will cruise past Jupiter at a distance of 2.5 million km and use the giant planet's gravitational pull to redirect the craft toward Pluto (which it will reach in 2015) as it inspects Jupiter and its moons. Cassini will still be circling Saturn, and a growing armada of spacecraft will continue to patrol Mars, including the Exploration Rovers. Across the Pond, the European Space Agency's Venus Express will be building up an unprecedented trove of data on the climate and atmosphere of Earth's parched, burnt, acidic sister world. In billions of years, Earth is destined to wind up like Venus as the sun ages and warms. Perspective from this era of interplanetary prospecting will help reveal our planet's complexities.