Water on Mars?
NASA Mission Control: Main engine start. Zero and lift off of the Atlas Five with Curiosity, seeking clues to the planetary puzzle about life on Mars.
The latest news from Mars is in fact so old that it makes Mars sound like a different planet. I’m Jim Metzner and this is the Pulse of the Planet. Bob Berman is an editor and columnist for Astronomy Magazine.
Berman: Recently, from Curiosity and other probes, we’ve found minerals on Mars that are only formed in the presence of water. So, Mars obviously had water in the past, and this interests us greatly. Mars has dried-out looking river channels that were made long ago. There’s no longer any flowing water in them, but they could’ve only been created by flowing water in the past.
Is there water on the surface of Mars now?
Berman: What’s intriguing is that you cannot have water right now on Mars because the atmosphere is too thin. Water only exists under pressure. In fact, as you reduce our air pressure, the water boils off faster and faster.
Go up any mountain, and every 500 feet water boils one degree less and less. By the time you’ve gotten to the top of Mount Everest, water boils before it’s hot. So, on Mars water boils immediately. You can’t have it. So, obviously, Mars must’ve been very different in the past to have shown all this evidence of past water. If there is water there now, it would have to be underground.
What was ancient Mars like?
Berman: We know now that it must’ve had a thicker atmosphere in order to have water. Just three billion years ago, the sun was 30 percent cooler, and with such cooler temperatures, it would’ve made it easier for Mars to hold on to an atmosphere.
Mission Control: Looking good.
In future programs, we’ll take a hard look at whether humans colonize Mars. I’m Jim Metzner and this is the Pulse of the Planet.