The photographs were taken by the High Resolution Stereo Camera on board Mars Express, the European Space Agency probe which is exploring the planet.Scientists led by a University of Texas geologist report that data from an unmanned NASA space probe suggests there's much more ice on Mars than previously thought. The Mars Reconnaissance Orbiter, according to an article in the journal Science, has identified several dirt-covered glaciers - including one that is three times longer than the city of Los Angeles and up to a half-mile thick. The glaciers may be remnants of warmer conditions on the Red Planet.Earlier this year, another spacecraft, NASA's Phoenix Mars Lander, scratched below the dirt-covered plains of the planet's North Pole to uncover a glistening slab of ice. The latest findings, from a team of 11 scientists led by John W. Holt of the University of Texas, will appear in today's edition of Science, a publication of the American Association for the Advancement of Science. Mars is a cold, dry realm. But long channels and what appear to be watersheds in the rugged terrain suggest to some scientists that water once flowed or pooledgnals from the orbiter penetrated the dirt-covered features and were reflected back at velocities con on the planet. In addition, Mars may undergo periodic climate swings linked to changes in its axis. During these changes, the north pole dips, exposing the region to higher temperatures, possibly thawing the ice. The Mars Orbiter used radar to examine the Hellas Basin, an ancient asteroid impact region in the planet's southern hemisphere. The scientists supervising the 700 million project were interested in the area's gently sloping features at the edges of mountains and cliffs. The radar sisistent with radio waves passing through ice, the scientists said.The spacecraft also spotted similar sloping formations extending from cliffs in the northern hemisphere. If Mars once hosted a more substantial atmosphere and warmer climes, then water may have fostered some form of life. Water would prove valuable to future human explorers as well. Its chemical elements, oxygen and hydrogen, can be used as rocket propellants, and oxygen, of course, is a source of air for breathing.A giant patch of frozen water has been pictured nestled within an unnamed impact crater on Mars!The ice disc is located on Vastitas Borealis, a broad plain that covers much of Mars' far northern latitudes.The existence of the water-ice patch on Mars raises the prospect that past or present life will one day be detected.It also boosts the chances that manned missions could eventually be sent to the Red Planet - because they would probably need accessible water to survive.Highly visible The highly visible ice lake is sitting in a crater which is 35 km (23 miles) wide, with a maximum depth of about two km (1.2 miles).Scientists believe the water-ice is present all year round because the temperature and pressure are not sufficient to allow it to change states.Researchers studying the images are sure it is not frozen carbon dioxide (CO2), because CO2 ice had already disappeared from the north polar cap at the time the image was taken.The team has also been able to detect faint traces of water-ice along the rim of the crater and on the crater walls.Mars is covered with deep gorges, apparently carved out by rivers and glaciers, although most of the water vanished millions of years ago.Earlier this year, the European Space Agency detected what they called a huge "frozen sea", but it is located below a crust of surface deposits.Large reserves of water-ice are also known to be held at the poles on Mars, and probably at great depth at many locations around the planet.
Posted by Unknown
|
at
2:03 PM
