Mission to Mars finds water ice
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Thursday, August 7th, 2008

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On Earth, ice is just another reason to love or loath
winter, depending on where you live and how you feel about cold weather. On
Mars, ice is much more special than that — any evidence of frozen water on the
Red Planet suggests that life could have survived there at one time.
Now, scientists have gathered the first direct evidence of
water ice on Mars. The discovery came out of the Phoenix Mars Lander mission.
The lander settled onto Mars on May 25 and has been poking and prodding at the
planet’s soil ever since.
Soon after touching down, the lander’s robotic arm dug a trench
called Snow White near the northern pole of Mars. One of the layers of icy soil
the arm dug into was as hard as a concrete sidewalk, says mission specialist
Ray Arvidson of Washington University in St.
Louis. From Earth, Arvidson controls the lander’s
robotic arm, which uses several tools to collect samples for the lander’s other
instruments.
Arvidson directs the arm’s pinky-sized drill to loosen the
hard soil. Then he guides a scoop to pick up the loose bits. From there, the
shavings go into one of eight ovens that are part of Phoenix’s Thermal and Evolved-Gas Analyzer,
or TEGA. The ovens allow scientists to analyze the soil by baking it: Scientists
can tell which ingredients are in the soil because different ingredients melt
at different temperatures.
After a month of mechanical troubles, the research team was
finally able to bake its second sample. Some of the sample melted at 0°
Celsius, the melting point of ice. The instrument also detected water vapor
during the procedure. Both clues confirm the presence of water ice.
Previously, satellite images suggested that there might be
water ice near the Martian poles. But the new discovery is the first direct
confirmation that water ice currently exists anywhere on the Red Planet.
“Now, we have finally touched and tasted ice on Mars,” says
William Boynton, a mission coinvestigator and lead TEGA scientist. “And I can
say it tastes very fine.”
Originally, Phoenix
was scheduled to stop its exploration at the end of August. But the new
discovery is exciting enough that NASA officials plan to keep the lander alive
for 34 extra days — until late September.
Scientists will use this bonus time to learn about the soil
and atmosphere of Mars’ polar region. Now that the team has proof of water ice
on the Red Planet, they can begin to investigate whether the planet’s icy layer
of soil could have ever supported life.
Found in: Science News For Kids
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