- WASHINGTON -- Ice crystals strewn across the Moon's poles. Valleys on Mars
where rivers once flowed. The possibility that Jupiter's moon Europa conceals
a slushy subterranean sea.
- Water has become an obsession among planetary
scientists and astronomers now designing an armada of space probes to look
for it or its mineral remains.
- "It's absolutely central to everything
we're doing," said Steven Squyres, a Cornell University astronomer
and the principal designer of NASA's Athena Mars rover, scheduled for launch
in 2001. "The likelihood that water might have existed in a particular
location has a direct effect on our consideration of possible landing sites."
- The prevalence of water in the solar
system sets the stage for debate about life on other worlds and discussion
of where humans might eventually travel.
- The principal value of water is its central
role in creating life, at least as scientists now understand it. Liquid
water, as opposed to ice, is considered necessary to allow elements to
mix and eventually assemble into complex organics and possibly life. Scientists
have no theories to explain the formation of life without liquid water.
There is, however, some speculation about complex organics forming in other
fluids such as liquid methane.
- Water also speaks to climate. That water
once may have flowed on Mars has led scientists to conclude that it was
once a much warmer, wetter place than today, with its surface temperature
of 100 degrees below zero.
- Water in space also would be extremely
valuable for planetary wayfarers. The hydrogen in ice could be used to
make hydrogen fuel for deep space travel, while the oxygen could provide
air on colonies.
- "Our entire strategy for the study
of Mars is focused on three elements: Life, climate change and exploitable
resources," said Carl Pilcher, acting director for solar system exploration
at NASA. "And they all have one common element: water."