Saturday, June 21, 2008

Ice on Mars

June 20 (Bloomberg) -- The existence of ice on Mars was confirmed today by NASA scientists, the first time frozen water has been sampled on another planet. Water in liquid form is an essential ingredient for life.

Whitish, dice-sized chunks, which were dug from the rocky red soil and warmed in the sun, vanished four days after the National Aeronautics and Space Administration's Phoenix probe dug them up June 15. They confirm what NASA satellites have suggested for years: Frozen water exists several centimeters beneath Mars's surface.

Scientists believe ice exists on planets including Pluto, though Phoenix is the first probe to confirm it on the ground. The survey is part of NASA's theme in Mars exploration: follow the water.

``We've hit what we're looking for,'' said Mark Lemmon, an atmospheric scientist at Texas A&M University in College Station and co-investigator on the NASA project. ``The job now is to find out what's mixed in with the ice.'' He spoke at a press conference in Tucson, Arizona.

The Phoenix's robotic arm also hit a hard surface yesterday while digging in a different spot, raising scientists' hopes that they might uncover a larger ice layer to sample, NASA said.

``When I look over this flat plain of rock and dirt, it's amazing what we're looking at,'' said principal investigator Peter Smith of the University of Arizona in Tucson, which is co- managing the project. ``If you got a giant broom and swept if off, it's a big ice sheet.''

Ice Below Surface?

NASA satellites suggest about a quarter of Mars has ice beneath the surface, primarily at the polar regions.

The agency's plan is to gather up ice and dirt, then deliver it to the Phoenix's airtight ovens. The matchbox-size ovens will then bake the sample.

On Mars, the boiling point of water is just 4 degrees Celsius. Under the planet's faint atmosphere, the water will quickly vaporize, Smith said.

Before it does, the probe will analyze the samples for any long-chain carbon molecules such as amino acids, the building blocks of life.

``That's what you need to have for a habitable zone on Mars,'' Smith said.

This is a big deal for three reasons. One, the presence of water on Mars means that there could have been some kind of life on the planet at some point in the past. It is even possible that some remnant of that life could remain say as spores waiting for a more hospitable climate to return.

Two, the presence of water ice means that at some point in the future it might be possible to teraform Mars and make it suitable for humans to live there.

Three, and by far the most important in the short term is that frozen water on Mars means that it is far easier for a manned expedition to go there. Due to the distance involved any Mars expedition would have to spend one year on the red planet if there is water there then they don't have to waste rocket fuel sending a year's supply of water to Mars and they don't have to waste space on the landing craft bringing any down to the surface with them. It means that they can manufacture a breathable atmosphere and that they can produce rocket fuel for the return trip right there on the planet's surface.

The chance that we'll see humans walking on Mars in our lifetimes just went up significantly.