Yes, there is water on Mars (Didn’t we know that?)

In case you haven’t heard, NASA has come out and stated that the Phoenix Lander has <gasp of wonder> found ice on Mars. The little lander dug a cute little trench with its shovel and uncovered some white stuff that over the course of several days disappeared in a manner consistent with water ice sublimating (changing from ice to gas) and that was inconsistent with dry ice sublimating.

Let me state for the record that watching ice on Mars sublimate from up close is just cool. Being able to say, ice behaves on Mars the way we thought it would, is important.

Having said that, I also have to say that I really wish folks would quite saying that Phoenix discovered ice on Mars. Folks, if you’ve got a 10 inch or larger telescope, take it outside next time Mars is in the sky. If you see a big white blob toward the end of one of the poles, you have observed ice on Mars.

For the past several decades – since before I was born – we have known that Mars’ poles have ice caps that grow and shrink with the seasons in a manner consistent with a mixture of water ice and dry ice. As early as 1976, scientists were reporting on measurements of atmospheric water vapor on Mars using Viking data (see here). With the more recent rounds of rovers, we’ve seen clear evidence of sub-surface ice from neutrons the ice fails to jettison when hit with cosmic rays (see here), and the mars rovers have found all sorts of minerals that could only have formed in water. Thus, we have evidence of past liquid water, current water vapor, and current water ice.

This means, we knew that there was water ice on Mars. Really. We had all the evidence we needed.

What is so valuable about this latest discovery is it takes that knowledge to the next step. Science is a building process and we grow our understanding one data point at a time. From Earth we knew Mars had polar caps, but we also thought it had seas. Once we started getting there with space probes, we learned it is a desert world whose only moisture is frozen, or perhaps under high pressure beneath the surface (where maybe it occasionally spurts out of gully walls). We could identify what acted in every way like ice when viewed from space, so we sent probes first to bright sunny areas near the equator to dig around for minerals that required water to form (fairly low risk as far as going to Mars with a rover was concerned). Having found those minerals, we then sent a lander to go sit on the ice (higher risk since sunlight is at a premium and the seasons are more extreme.) Now, we have seen the ice really seriously up close. We still haven’t been able to do a chemical analysis of the water however. We’ve still only looked at it.

The next big break through will come in technologically tasting the ice to see what flavors – what minerals, isotope combos, and inclusions of gas – permeate the ice (never taste the yellow snow). We’re going to get there in the coming days and it is the result of that test that I’m waiting for.

We are building knowledge. This is good. We aren’t discovering Mars has ice. That’s old news. Instead, we’re discovering the characteristics of that ice, which is its own kind of cool.

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4 Comments

  1. Richard B. Drumm June 21, 2008 at 12:51 am #

    When (last week I believe) they had trouble getting the soil sample to go through the screen into the ovens I said to myself “I bet it’s full of ice crystals and is cohesive. It’ll take a few days for the ice to sublimate, then the sample will fall through.” This appears to have subsequently happened. I won’t hold my breath that they’ll actually get ice into the ovens, though.
    I hope I’m wrong, but… :sigh: I’ll bet I’m right. (I hate it when that happens and it’s something bad like getting no data.) Rats!
    Rich

  2. Brian June 21, 2008 at 9:57 am #

    It would be really neat to find some kind of microorganism in the water but I guess all estimates are that it will be of extremely high salinity, so much as to not support any kind of life. Well at least not like life here on Earth ;>

  3. Umair Rahat June 22, 2008 at 5:10 am #

    While we haven’t found life on Mars, the possibility of finding life is extremely high. Mars Science Laboratory might be the first scientific instrument (collectively) to confirm life on an other planet other than Earth.

  4. TD June 22, 2008 at 11:14 am #

    Pam, I absolutely agree with you. Astronomers have known about water ice at the Mars poles since at least the 1950’s, from spectroscopic measurements. If the Phoenix folks wanted to really find ice quickly, they could have landed right on top, at the Martian pole. The big question I hope they intend to answer is to find organic compounds (like the Sinton bands, also reported in the 1950’s.) Organic (carbon) compounds were not found by the Viking mass spectrometer, and this negative finding was the major reason the the other positive life detection readings of Viking were discounted as simple chemistry, not life. With all the mechanisms to move microbes thru space, it is almost inconceivable that Mars is sterile – Hopefully Phoenix will find evidence of life….. Frozen water – old news.

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