Mars is a cold, forbidding world. Yet even by Martian standards, the landing site for the Phoenix mission is nippy -- the kind of place that makes the frozen tundra of Lambeau Field seem like a Jamaican beach by comparison.
Phoenix is scheduled to touch down on Sunday, north of Mars's Arctic Circle. Over the next three months, it'll dig a series of trenches in the ground and scoop up small amounts of soil. It'll dump the samples into a chemistry set that will search for water and organic chemicals -- the building blocks of life.
Scientists chose the northern plains for several reasons.
For one thing, spacecraft in orbit around Mars have found evidence of vast deposits of ice mixed with the soil there. Phoenix is designed to search for water and the chemistry of life, and the northern landing site offers the best chance to find them.
For another, the landing site is near the edge of the winter ice cap. It's summertime now, so the ice has pulled back, exposing soil that's been covered for months. This will help Phoenix learn more about the interplay among the ice caps, the soil, and the Martian atmosphere.
And finally, the lander will have abundant sunlight to keep it warm in the icy northern plains.
By the end of its 90-day mission, though, the Sun will set and bitter cold will return to the Martian plains -- freezing the lander and eventually encasing it in ice.
We'll have more about Phoenix tomorrow.
Script by Damond Benningfield, Copyright 2008
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