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The Phoenix Lander's thirst for Martian waterSince the Phoenix Lander touched down near the north pole of Mars, the mission to find water has been on. CNET News.com's Kara Tsuboi interviews planetary scientist Paul Doherty about Martian water, ice, and snowflakes, and why finding any of them would...
[ Background Music ] >> I'm Kara Tsuboi CNET News.com. I'm here at San Francisco's Exploratorium to talk to Paul Doherty about the Phoenix Lander. Paul is a senior scientist here and a planetary scientist with a degree from MIT. Thanks for joining us. >> It's great to be here and I'm really excited by this successful landing of the Phoenix Lander. >> Tell me about the different water properties on Mars. >> On Mars, the atmospheric pressure is much less than the pressure that's squeezing in on us here on the earth and that makes a big difference for water. So let me sort of--can I show you about the pressures? >> Please do. >> I've got this 5 foot long steel rod that if I put it on my hand, that's the atmospheric pressure that's squeezing every inch of your body. But when we go to Mars the atmospheric pressure on Mars is like that. It's 100 times less than the atmospheric pressure on earth. >> So to boil that water takes a lot less energy. >> That's right! It takes a lot lower temperature. So from most of Mars, half of Mars, water will boil at zero degree Celsius at the freezing point. >> So the water in this test tube and by altering the pressure you can simulate how much is actually forcing on it in Mars' atmosphere. >> So right now the earth's atmosphere is pushing down on these, pressing that water together so it doesn't boil at room temperature. But if I pull out on this as you see me pulling out, I reduce the pressure and when I--I snap it there a bit, when I reduce the pressure it actually fizzes and that fizzing is boiling. There it nicely fizzes at room temperature. >> And I hope we can see photos of that. That's sort of the planet that they're gonna be taking pictures from the Phoenix and sending 'em back? >> They will. We'll actually see pictures. They're gonna--they've looked around already and they don't see any bare naked ice at the moment but they have an arm with a scoop on it and they're gonna dig down into the soil and they expect from orbital observations of different nuclei and molecules above the surface that they're gonna find ice within half a meter, about 20 inches down at least. So they're gonna dig, they'll expose some ice and we'll be able to see this solid ice on Mars. >> If there's ice on Mars, there's gotta be snow flakes? >> That's right. So I wanted to find out what's the shape of a snowflake on Mars but on Mars in the winter, snowflakes are not made of water, they're made of dry ice, carbon dioxide ice like on earth and I found out that nobody knew the shape of carbon dioxide snowflakes. So in my lab on earth I made a Mars atmosphere, I created a snowstorm, a Martian snowstorm and I grew Martian snowflakes and took the picture of them. >> How do they look different from an earth's snowflake? >> So this is my plastic model of a Martian snowflake. It's a cube with all four corners on top and all four corners on the bottom cut off and that's called a cuboctahedra. >> And speaking like in a big picture, what does all of this research and exploration really mean for our space race? For what this country is doing as far as figuring out life in other planet? >> Well one of the great important philosophical questions of all time is what is life and where is life, so does life exists only on the planet earth as we know it? Or is there life elsewhere in the universe and Mars is like the first baby step into the universe searching for other forms of life. So we'll be there with a chemistry lab looking for ice, water ice and liquid water, because at some times in Mars' history, it can warm up at this region of Mars where we landed and make liquid water and see if trapped within the ice, there's some sign that life exists or existed on Mars. >> Very well, thank you very much Paul. >> Oh good to be here. >> I appreciate the demonstration. I'm Kara Tsuboi, CNET News.com. ^M00:03:40 [ Music ]