Posted on 12/03/2005 4:24:53 AM PST by BenLurkin
PARIS (AFP) - The European spacecraft Mars Express has added powerful evidence to the belief that water once covered Mars and large reserves of precious ice lurk close to the surface today, studies presented said.
Surrounding Mars' north pole are underground "layered deposits" that are believed to be fine strata of ice, according to research presented at the headquarters here of the European Space Agency (ESA).
The find is "nearly pure, cold water ice," with only two percent contamination by dust.
Beneath these deposits are large amounts of sand that is probably "cemented" with water ice.
The data was collected in three swings over the Red Planet, on June 26, July 6 and July 9, by the ESA orbiter after it had deployed a mighty ground-scanning radar called MARSIS, that delved to a kilometer (3,250 feet) below the planet's surface.
Meanwhile, scientists using a near-infrared spectrometer called OMEGA found wide-ranging clays called phyllosilicates -- a telltale for water, for they are formed when volcanic basalt rocks are immersed in water for a long period.
They conclude that oceans covered Mars at the end of the so-called Noachian era, which concluded between 3.5 and 3.8 billion years ago. If so, it means that Mars was watery in its childhood: the planet, like Earth, was formed around 4.6 billion years ago.
In recent years, data sent back by orbiting spacecraft and two US rovers has suggested that the planet was once awash in water and that the precious substance could still exist in the form of ice.
Finding the water could determine whether the planet once sustained life, and maybe even now harbours it, perhaps in microbial form. And a reservoir of water would be vital for a planned manned mission to the planet.
But the evidence until now has been sketchy, based mainly on images of the Martian surface, taken from land and at the surface, which show a planet dismayingly dry and dusty.
Mars' subsurface is "the missing third dimension," said Giovanni Picardi, a University of Rome scientist who is the MARSIS chief investigator.
Mars Express, Europe's first solo mission to explore another planet, arrived at Mars on December 25, 2003.
It dropped a small robot lander, Beagle 2, that disappeared without trace, and then experienced a 13-month delay in deploying the long arms of the MARSIS radar, one of the most important instruments in its scientific package.
MARSIS is designed to send powerful low-frequency radio waves which are capable of penetrating the ground to a depth of several kilometers (1.5 miles).
The reflected energy is then picked up by the orbiter and transcribed to give an image of Mars's sub-surface structure.
In addition to finding evidence of the polar ice, MARSIS also spotted a remarkable structure buried just under the surface in the northern lowlands of Chryse Planitia, in Mars' northern equatorial region.
Measuring 250 kilometers (150 miles) across and roughly ring-shaped, the phenomenon could be an impact from an asteroid or other space rock.
Where Mars' water went is one of the big challenges facing the unmanned space explorers on Mars.
One theory is that around 3.5 billion years ago, the planet somehow lost its core-driven magnetic field, a shield that protected it against the fierce buffeting of particles from the Sun.
Without this, the planet's thick carbon dioxide atmosphere was progressively shredded by the solar wind and its oceans slowly evaporated, leaving only residual water in the form of ice.
The OMEGA study appears in Thursday's issue of Nature, the British weekly science journal, while the MARSIS study is published online by the US journal Science.
More on Mars ice.
Not surprising.
The three most common elements in the universe:
Hydrogen
Helium
Oxygen
The helium isn't good for much beyond filling dirigibles, but all that hydrogen and oxygen makes water a likely find. It's there on Mars (enough to cover the planet in a 200-foot-deep ocean) and it's there on Europa (more than the total amount of water on earth). Water, water, everywhere, just no one there to drink it.
Neat!
'Course it's watery, hence all the canals :-)
so on Mars,with an air pressure of about 1/100th of an atmosphere, why doesn't the ice simply sublime off into water vapor?
Without this, the planet's thick carbon dioxide atmosphere was progressively shredded by the solar wind and its oceans slowly evaporated, leaving only residual water in the form of ice.
The ONLY conclusion here folks any current Earthling can form, is that 3.5 bil. years ago, a vast Martian civilization had SO MANY CO2-belching SUV's, that it destroyed the atmosphere (filled it with CO2) and destroyed the magnetic field (presumably by putting too much metal on the planet surface).
"The three most common elements in the universe:
Hydrogen
Helium
Oxygen"
Who took away all the green cheese?
NASA has had two rovers down on Mars for nearly a year now (the little guys just keep going on and on.)
http://marsrovers.jpl.nasa.gov/home/index.html
It is pretty clear there is nothing there really, just a bunch of red rocks.
It is also clear that winds and dust storms are not anywhere near as dangerous as we once thought. Mars is pretty peaceful place.
We'll send a manned mission there someday soon and investigate the ice, life, 2 mile deep canyons in person and know for sure.
I knew what you meant - I mistype all the time - but had to share the humorous vision you gave me:)
What until the Left gets ahold of this:
"Without this, the planet's thick carbon dioxide atmosphere was progressively shredded by the solar wind and its oceans slowly evaporated, leaving only residual water in the form of ice."
Wot mean ye that there be no Teutonic activity?
Typos can be fun!
Uh--We have been walking around the Mary surface for months with sampling instruments and this was a European fly-by. Given how many previous Mars "characteristics" have been corrected once we actually landed on Mars and collected ground data, I think fly-by hypothses should be viewed as potentially open to significant modification.
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