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Posted by Paul A. Heckert May 26, 2008 |
Mars, the blood red god of war, has dominated our evening skies for the past several months, but it has dominated our collective imaginations for much longer.
As the latest chapter in our long term quest to explore Mars, NASA just landed the Phoenix mission on Mars' polar ice cap. The focus of the Phoenix lander and indeed much of our Mars exploration program is to answer one question. Is there or has there ever been life on Mars? Phoenix is not equipped to detect life directly, rather it will study the possibility of liquid water.
Why should we care?
We live in a universe of unimaginable vastness. Are we alone in this universe, or is it teeming with life? Based simply on the vastness of the universe, most astronomers, including me, think that we could not possibly be alone. But, we have so far found not one shred of credible evidence that there is life someplace else in the universe. This question is therefore still unanswered.
It would be less lonely if Earth life has a companion out there, so we are looking. Mars is the closest moon or planet with a reasonable possibility of life. Jupiter's moon, Europa, is also a likely candidate, but it is farther away and more difficult to get to. So we start by exploring Mars.
We still don't know if life is something that forms easily or only very rarely. If we find evidence of life or past life on Mars, then life probably arises easily and is common in the universe. If we find no such evidence, then on to Europa. We are just trying to make our vast universe a little less lonely.