Water Everywhere on Mars, But Is Any of It Ever Liquid?

摘要

Water on Mars is nothing new. It's been "discovered" many times, but it's always frozen. The liquid form would be so much more exciting in an astrobiological way. At the meeting, meteorologist Nilton Renno of the University of Michigan, Ann Arbor, and 21 of his teammates on the Phoenix mission to Mars reported Phoenix observations buttressed with thermodynamic arguments that suggest to Renno, at least, that briny liquid water exists at the Phoenix site. Not everyone agrees.rnRenno starts with the discovery of both ice and salts in the soil of the Phoenix landing site. As he sees it, temperature swings from day to day or millennium to millennium should drive water from the ice into the salts, which become wet and dissolve. Even when it gets much colder, the briny water will stay liquid longer.