Recent Liquid Water on the Surface of Mars?

MGS image of new water flow
MGS image (full-size) of one of the new deposits. Credit: NASA/JPL/Malin Space Science Systems

In a previous post, I discussed the Mars Global Surveyor (MGS). It has returned vast amounts of data over the several years it has been orbiting Mars, but unfortunately seems to have finally stopped functioning. In that post, I mentioned that MGS had taken photographs of gullies that were thought to have been created by liquid water flowing on the surface—in some cases, the gullies seemed to have formed rather recently, but it was uncertain how recently the water may have flowed. The MGS team looked for evidence of change from previous photographs. In a press release today, they write

In June 2000, we reported the discovery, using the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), of very youthful-appearing gullies found on slopes at middle and high latitudes on Mars. Many examples were presented in our captioned web releases and in a paper published in the journal, Science. Since that time, tens of thousands of gullies have been imaged by all of the Mars orbiting spacecraft: Mars Global Surveyor, Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter.

During the years since the original June 2000 report, the MGS MOC was used to test the hypothesis that the gullies may be so young that some of them could still be active today. The way the test was conducted was very simple: re-image gullies previously seen by MOC and see if anything changed.

In two cases, something changed.

MGS image of changed deposit
MGS image (full-size) of another new deposit. Credit: NASA/JPL/Malin Space Science Systems

The reports will be published in this Friday’s Science. This news is exciting for a number of reasons. One, subterranean liquid water sources could be of considerable use to future Martian colonists and explorers (if indeed such a word as subterranean may be used to describe locations below the surface of Mars). Also, this significantly increases the probability that life could be found on Mars. The planet was probably warm and wet several billion years ago, and though the atmosphere is too thin and Mars is too cold for liquid water at its surface today—there does appear to be water ice at the poles—life could have persisted or developed in underground deposits.

Though liquid water seems the likely explanation, there are possible mechanisms for this change, and it is prudent to remain skeptical. We may expect additional investigation from the newly arrived Mars Reconnaissance Orbiter with its high-resolution camera, and NASA is planning to launch the Phoenix spacecraft next year. It will land on Mars the following year, intensifying the study of our neighbor planet.

I strongly recommend the Bad Astronomy blog entry for further information and explanation. See also the two press releases, and a CNN article.

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7 thoughts on “Recent Liquid Water on the Surface of Mars?

  1. Re the subterranean term: we can simply substitute “submartian” for any reference to, um, submartian water.

  2. I’m so curious about the next news about it. But I’m pessimist. The surface of Mars has a too large daily temperature difference. Even if there is some water, I don’t see too much chance for a possible life form.

    And BTW, how can it be liquid in those temperatures?

  3. UTC,
    I don’t have any hard data on hand, but I’m remembering some conversations I’ve had with astrobiologists at JPL.. (I’m peripherally involved with a research project at my universe that is developing spectrometers as sensors for atmospheric biomarker gases for use on Mars.) It seems that while the surface temperature is highly variable, temperatures just a few meters below the surface could be substantially warmer. So some scientists at least think there could be liquid water below the surface across much of the planet.
    Others look for signs of geothermal activity. This could be the most reasonable explanation for the recent (but isolated) water flows. Microorganisms on earth can survive in very hot and cold environments, and something like a subterranean geothermal plume could have (relatively) a lot of action.

  4. → Penseroso It’s interesting—there are many terms that are specialized for Earth; I wonder if they will be generalized or if new terms will be coined. It wasn’t that long ago that I saw areology used for Martian studies the way geology is used for Earth. But of course it would be silly to have different terms for each body; it appears that planetary geology or similar terms are now being used, even though traditionally, geo- is supposed to refer specifically to Earth.

    → Ncurse I believe Mr. Keller is right; while water cannot remain liquid on the surface, it may be liquid below ground, which is where life could potentially thrive.

  5. I think that we should just plant a whole bunch of trees cover them only sun can get in keep an on going water and in 100 years and theres the oxygen

  6. I’m afraid it’s not quite that simple. Trees, unmodified, would not be able to grow on Mars. Among other reasons, there would be insufficient (if any) water in the soil; essential trace nutrients would be lacking, it would be too cold (the temperature is typically well below freezing), the sunlight would not be intense enough (as Mars is significantly farther from the sun than Earth is), and the atmosphere is too thin (less than 1% the surface pressure of Earth’s atmosphere).

    However, you have the fundamental idea behind terraforming correct: plans often begin with a photosynthetic organism or other autotroph (often bacteria) to begin production of oxygen.

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