Dice-size crumbs of bright material have vanished from inside a trench where they were photographed by NASA’s Phoenix Mars Lander four days ago, convincing scientists that the material was frozen water that vaporized after digging exposed it.
“It must be ice,” said Phoenix Principal Investigator Peter Smith of the University of Arizona, Tucson. “These little clumps completely disappearing over the course of a few days, that is perfect evidence that it’s ice. There had been some question whether the bright material was salt. Salt can’t do that.”
It’s so interesting how so many of these news articles are making it sound like the existence of ice on mars is the big news. You can see ice on mars with just a home telescope.
Possibly but from what I’ve read the extreme cold temps on Mars are -80 C and we all know dry ice on earth is like -78 C with earth pressures. Mars has no pressure so I believe that would make the formation of dry ice more difficult?
I’m not a chemist, but I took chemistry in high school!
Sure it’s possible. Look at the phase diagram for CO2 which shows what phase state CO2 would be in at what temp and/or pressure. You’ll notice that provided temperature are sufficiently low enough (as they would be on Mars), low pressure does not necessarily prohibit dry ice formation. But that is where my knowledge base ends. Does Mars have some atmospheric pressure? I assume it has more than absolutely none.
It’s possible within the ranges of the Martian atmospheric temperatures and pressures to be either water or CO2, but given that the lander probably has instruments to measure that stuff… I would believe NASA. It’s an absolutely trivial calculation.
In KSR’s Red Mars, Green Mars, Blue Mars series, they talk about storms with like 300 MPH winds that you could walk around in without much trouble as the air was so thin.
Mars has a very thin atmosphere made mostly of carbon dioxide. The surface pressure on Mars is only about 0.7% of the average surface pressure at sea level on Earth.
