Lander Finds Ice on Mars

Tashah · 06-21-08, 04:31 AM

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Lander Finds Ice on Mars, Scientists Say
Discovery Is Key Clue In Determining Whether Planet Supported Life

By David Brown
Washington Post Staff Writer
Saturday, June 21, 2008

Scientists with the Phoenix Mars mission yesterday declared for certain that there is ice on the Red Planet, putting them an essential step closer to answering the question that has driven three decades of Mars exploration and centuries of Earth-bound speculation: Could there have been life there?

Pictures beamed 170 million miles to Earth from the Phoenix lander atop Mars's northern polar plain erased any doubt about the presence of ice, they said. Last Sunday, several dice-size solids were observed at the bottom of a trench that had been dug by Phoenix's robotic arm. On Thursday, they were gone.

The only reasonable explanation, the scientists said, is that the objects were pieces of ice that evaporated into the dry Martian atmosphere through a process called sublimation. And the presence of ice means that Mars might once have had liquid water, which is essential for life -- at least as it is known on Earth.

One possibility was that it was salt of some sort. But ice was always the more likely explanation. "Salt does not behave like that," said Mark Lemmon, a scientist at Texas A&M University who is in charge of Phoenix's stereo surface imager. "We found what we were looking for. This tells us we have water ice within reach of the arm."

Source: Washington Post

Very possibly a “Eureka!” moment in space exploration.

GarzaUK · 06-21-08, 05:36 AM

I'm interested if this ice permaforst in the Martian soil contains methane, like it does on Earth. If this is the case, terra-forming Mars to be like Earth became a whole lot simplier and quicker

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Exciting stuff. But does water on another planet mean there definitely was life at some point? I don't know.

Tashah · 06-21-08, 05:44 AM

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Originally Posted by GarzaUK

Exciting stuff. But does water on another planet mean there definitely was life at some point? I don't know.

From the Phoenix Mars Mission web site...

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"The truth we're looking for is not just looking at ice. It is in finding out the minerals, chemicals and hopefully the organic materials associated with these discoveries," said Smith

The mission has the right instruments for analyzing soil and ice to determine whether the local environment just below the surface of far-northern Mars has ever been favorable for microbial life. Key factors are whether the water ever becomes available as a liquid and whether organic compounds are present that could provide chemical building blocks and energy for life.

Phoenix Mars Mission - Home

WI Crippler · 06-21-08, 11:25 AM

Indeed this is a very exciting discovery. Hopefully this "smoke" will lead to the bigger discovery of the "fire" we are searching for, in regards to proof that life has evolved elsewhere.

WI Crippler · 06-21-08, 06:20 PM

I did have a question pass through my mind while thinking about this today. Isn't the temperature on Mars something like -40F or C and can plummet even further? How would ice melt once exposed to freezing temperatures? Is some kind of chemical reaction to the atmosphere that would be different than here on earth? Exposure to UV rays? I'm not sure, but it would seem like it should stay frozen.

metreon · 06-21-08, 10:15 PM

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Originally Posted by WI Crippler

Isn't the temperature on Mars something like -40F or C and can plummet even further? How would ice melt once exposed to freezing temperatures?

Since the partial pressure of water vapor as well as other gases in the Martian atmosphere is low, ice can sublimate, going directly from solid to vapor. It happens all the time on Earth also and is not that unusual. Also the temperature rises much higher during the day since the atmosphere is thin (the pressure is about 1/100 that of Earth). A lot of direct radiative heating and cooling going on there.

Below is a phase diagram showing the points at which water goes directly from solid to vapor. Notice that below freezing and 1 atm there is no liquid phase to water, so you wouldn't expect to see "melting" in that cold an environment and at such low pressures.

jfuh · 06-21-08, 11:08 PM

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Originally Posted by WI Crippler

I did have a question pass through my mind while thinking about this today. Isn't the temperature on Mars something like -40F or C and can plummet even further? How would ice melt once exposed to freezing temperatures? Is some kind of chemical reaction to the atmosphere that would be different than here on earth? Exposure to UV rays? I'm not sure, but it would seem like it should stay frozen.

Because Mar's atmosphere is not as thick as Earth's because the planet doesn't have as much gravity the atmospheric pressure on Mars is much smaller than it is on earth.
So for the same reason that water does not boil at 100C when you hike in the mountains is the same reason that ice can "evaporate" on Mars.

WI Crippler · 06-21-08, 11:40 PM

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Originally Posted by jfuh

So for the same reason that water does not boil at 100C when you hike in the mountains is the same reason that ice can "evaporate" on Mars.

Hmm, I knew this, but never thought to apply it in reverse.

Mach · 06-23-08, 12:12 PM

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Originally Posted by GarzaUK

I'm interested if this ice permaforst in the Martian soil contains methane, like it does on Earth. If this is the case, terra-forming Mars to be like Earth became a whole lot simplier and quicker

.
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Not to mention the fact that we'd have ready-made ice to cool our beer after the long days of construction on that martian soil.

-Mach

GarzaUK · 06-25-08, 06:10 AM

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Originally Posted by Mach

Not to mention the fact that we'd have ready-made ice to cool our beer after the long days of construction on that martian soil.

-Mach

Of course, the most important things come first!