Water ice found on Mars

Which is pretty cool:


Mars Phoenix Tweets: "We Have ICE!"
By Alexis Madrigal EmailJune 19, 2008 | 7:20:57 PMCategories: Mars

Dodo_020_0242_2There is water ice on Mars within reach of the Mars Phoenix Lander, NASA scientists announced Thursday.

Photographic evidence settles the debate over the nature of the white material seen in photographs sent back by the craft. As seen in lower left of this image, chunks of the ice sublimed (changed directly from solid to gas) over the course of four days, after the lander's digging exposed them.

"It must be ice," said the Phoenix Lander's lead investigator, Peter Smith. "These little clumps completely disappearing over the course of a few days, that is perfect evidence that it's ice."

The confirmation that water ice exists in the area directly surrounding the lander is big and good news for the Martian mission. NASA's stated goal for the Mars Phoenix was to find exactly this -- water ice -- and then analyze it. With the latest news, the first step is accomplished. All that's left now is to get the water into the Phoenix's instruments, a task which has occasionally proven more difficult than anticipated.

Still, this is the best opportunity that humanity has ever had to analyze extraterrestrial water in any form. That had the Phoenix Lander's persona fired up.

"Are you ready to celebrate? Well, get ready: We have ICE!!!!! Yes, ICE, *WATER ICE* on Mars! w00t!!! Best day ever!!" the Mars Phoenix Lander tweeted at about 5:15 pm.

Their suspicions about water ice beneath the surface of Mars confirmed, scientists and the world will have renewed interest in the outcome of the soil analyses currently being conducted by the lander.

The samples are being examined for traces of organic molecules, among other substances, but the lander does not have instruments that could directly detect life.

http://blog.wired.com/wiredscience/2008/06/mars-phoenix-tw.html

 

yeah, because water ice sublimates here all the time...

how do they know it's not dry ice?

 

I don't think it's cold enough on Mars for nitrogen to exist as a natural solid. Nitrogen's freeze point is 63K, while low temperature on Mars is estimated to be 133K.

 

I thought dry ice was CO2. It's melting point is something like -60 or so.

I can't remember, but perhaps the lower pressure allows h2o to sublimate on mars?

 

i'm talking about CO2

 

Well, of course you were. I was incorrect. Sorry 'bout that. Precipitation of CO2 comes at 195K.

 

I think that's the theory.

 

So, depending on atmospheric pressure, ice would sublimate below around 0c

 

Good. Now I can get ice in my coke.

 

Precipitation?

 

liquid CO2?

 

You mean deposistion?

 

Nowhere near the pressures needed for liquid co2 on mars. Deposition, maybe. At earth pressures.

 

Sure. Whatever the reverse of sublimination is. I always hear snowfall referred to as precipitation, so I figured that it worked for gas to solid as well as gas to liquid.

 

deposition <=> sublimation

condensation <=> vaporization

melting <=> fusion


Snowfall is precipitation, but so of course is rainfall. Snowflakes are formed by deposition of water vapor onto nuclei. The freezing of liquid water gives you sleet. In chemistry, precipitation is the formation of solids by a chemical reaction within a solution.

 

we just call that fog

or

Con den sa tion

con den sa tion

 

:gary:



Cool, thanks.

 

The bigger question is whether they determined if air oxygen was present.

 

You can have life without oxygen, but not without water, right?

 

IMO, a complete waste of taxpayers dollars. Yes, space is cool but wees got some issues down here.