The Phoenix Lander has, apparently, found evidence of frozen water on Mars:
Now, scientists will be able to tackle the main question they hope to answer: Did the ice ever melt and turn Mars into a habitable place?
In a photograph released Thursday evening of a trench that the Phoenix Mars lander has dug into the Martian soil, some white patches that were seen earlier in the week have shrunk, and eight small chunks have disappeared. Until now, scientists were not sure if the white material was ice or some kind of salt.
When exposed to air, water ice can change into water vapor, a process known as sublimation. Salt, on the other hand, is not capable of such a vanishing act.
“It must be ice,” said Dr. Peter H. Smith of the University of Arizona, the mission’s principal investigator. “The whole science team thinks this. I think we feel this is definite proof that these are little chunks of icy material.”
Water ice on the surface of Mars is not a new discovery. Scientists have known that the permanent ice cap at Mars’s north pole is made of ice. In 2002, measurements by the orbiting Mars Odyssey spacecraft found evidence for vastly larger quantities of ice not far beneath the surface.
In light of the Odyssey findings, the Phoenix mission was designed to land in the northern arctic plains and dig trenches in the soil into the ice layer, believed to be a few inches under the surface. Still, to actually see the ice was “tremendously exciting,” Dr. Smith said. “One of the biggest fears I’ve had on the mission is that we’d dig and dig and never find anything.”
Liquid water transforms minerals, so impurities in the ice could tell much about the climate history. While Mars is too cold for liquid water, in the past, if its axis occasionally tipped over, the polar regions might have warmed above freezing during the summer.
Liquid water is an essential ingredient for life, and this area may have been, at least intermittently, a habitable environment in Mars’s geologically recent past, in the past 10 million years or so.
Very cool.
June 20th, 2008 at 10:08 am
There’s dry river beds all over Mars, so there MUST have been liquid water at some point.
June 20th, 2008 at 10:16 am
True, but this is significant because up until now, the only place we know water exists on Mars is at the polar caps. Finding evidence of subterranean (I guess “subterranean” isn’t the right word since we’re dealing with Mars, is it ?) water may provide evidence of where a lot of the water that scientists think once flowed on the surface may have gone.
June 20th, 2008 at 11:53 am
“Subarean”, perhaps?