PASADENA, United States, March 15 (Xinhua) --
Scientists have discovered that the southern polar region of Mars contains
enough ice to cover the planet in a layer of water 36 feet (11 meters) deep.
Scientists at the Jet Propulsion Laboratory (JPL) in
Pasadena, California, announced that an instrument on the European Space
Agency's Mars Express determined that the ice on the south pole goes at least
2.3 miles (3.7 km) below the surface.
The discovery was the result of joint efforts by the
Italian Space Agency and researchers at the JPL, which is part of the U.S.
National Aeronautics and Space Administration (NASA). The team has been working
to determine the thickness of the frozen water on Mars.
The study's findings are published in Thursday's
online edition of "Science."
"The south pole's layered deposits of Mars cover an
area bigger than Texas. The amount of water they contain has been estimated
before, but never with the level of confidence this radar makes possible," said
Jeffrey Plaut of JPL in Pasandena, near Los Angeles.
Scientists are using the Mars Advanced Radar for
Subsurface and Ionospheric Sounding, otherwise known as MARSIS, to also map the
thickness of similar deposits on the north pole of Mars.
"MARSIS is showing itself to be a very powerful tool
to probe underneath the Martian surface, and it's showing how our team's goals,
such as probing the polar layered deposits, are being successfully achieved,"
said Giovanni Picardi, principal investigator of the project.
"Not only is MARSIS providing us with the first-ever
views of Mars' subsurface at those depths, but the details we are seeing are
truly amazing."
The polar layered deposits hold most of the known
water on Mars, although other areas of the planet appear to have been very wet
at other times, according to the researchers.
Discovering the history of water on Mars is key to
determining whether the planet ever supported life.
The frozen water deposits are also helping
researchers learn more about the internal structures of Mars.
"We didn't really know where the bottom of the
deposit was," Plaut said. "Now we can see that the crust has not been depressed
by the weight of the ice as it would be on Earth. The crust and upper mantle of
Mars are stiffer than the Earth's, probably because the interior of Mars is so
much colder."