Liquid Water On Mars
Well, maybe. Within a couple of days of each other, reports of two possible evidence for liquid water on the red planet. The first shows blobs on the legs of the Phoenix lander that grew and changed shape and position, just like drops of water. The second suggests that a recently-formed gully that resembles those carved by running water may have been created by brines bursting from a point in the surface. The surface of Mars is colder than the freezing point of water, but high concentrations of chemicals - perchlorates in the case of the droplets on the Phoenix lander; ferric sulphate in the case of the brines that may have formed the gully - could act as anti-freeze and reduce the evaporation rate. So much for Bradbury's crystalline canals - this stuff would be more like the sludge that leaks out of toxic waste dumps.
Unfortunately, the concentrations of salts necessary to keep water liquid at minus seventy degrees Centigrade would rule out the possibility of life as we know it. "If you tried to put any kind of life-form you can imagine on Earth in a brine solution of that sort, the water would be sucked out of the cells," according to Phoenix mission leader Peter Smith. Yeah, but what about life as we don't (yet) know it?
Meanwhile, the Dawn probe has just swung past Mars on its way to the asteroid Vesta, boosting its velocity and fractionally slowing the planet.
"The flyby will cause Mars to slow in its orbit enough that after one year, its position will be off by about the width of an atom. If you add that up, it will take about 180 million years for Mars to be out of position by one inch (2.5 cm)," Rayman said. "We appreciate Mars making that sacrifice so Dawn can conduct its exciting mission of discovery in the asteroid belt."The things we humans can do.