That’s right, the Phoenix Mars lander may have uncovered what appears to be a layer of frozen water with its descent thrusters. The substance has not yet been analyzed, so saying anything for certain would be premature.
The discovery of ice would be exciting, but perhaps not too surprising, as ice is known to exist in large quantities on Mars. In fact, according to an article on the Jet Propulsion Laboratory’s website, the southern polar region contains enough water to cover the entire planet to a depth of 11 meters, if global warming becomes a problem there.
The discovery of ice within the reach of Phoenix, however, would be exciting, because water is considered by most scientists to be essential for the development of life, and certainly of life of our variety. Since part of the mission of the Phoenix is to search for organic molecules, and hence the building blocks of life, the discovery of water would be an encouraging first step.
As I see it, this find is exciting for another reason: many scientists believe that life could have originated in ice. This blog post is an excellent summary of the idea. Pockets of liquid water can persist within ice of incredibly low temperatures, and certain biologically important reactions appear to be facilitated by the cold, rather than hampered. If this idea proves out, the ice on Mars may be among the best places to search for signs of life.