Stranger Fruit

Ice on Mars


To quote the Lander: “Are you ready to celebrate? Well, get ready: We have ICE!!!!! Yes, ICE, *WATER ICE* on Mars! w00t!!! Best day ever!!” More here.


  1. #1 Colugo
    June 19, 2008

    Looks like Dan Quayle was right.

  2. #2 megan
    June 19, 2008

    time to pull out the snoopy snow cone machine. slushies for everyone!

  3. #3 Mike P
    June 20, 2008


  4. #4 Cuttlefish
    June 20, 2008

    It’s out of this world! And so very nice,
    In the barrens of Mars, to have dug up some ice!
    My prediction today? That intrepid explorers
    Will soon find the signs of some Naked Ice Borers!

  5. #5 S. C. Hartman
    June 20, 2008

    Can they rule out solid CO2 (Dry Ice)? I haven’t seen this possibility mentioned anywhere, and unless/until they do the claim of solid evidence for water ice is still a bit fluid, IMO. Might there be a big underground “carbonifier” of solid CO2 that keeps the soil temperature low? There’s something hard down there. What is it?

  6. #6 Ian
    June 20, 2008

    Hartman: “…the claim of solid evidence for water ice is still a bit fluid…”

    Beautifully phrased! Made my day.

  7. #7 ehoffman
    June 20, 2008

    It totally made my day to see that come across my Twitter feed. Love it when machines say “w00t” 🙂

  8. #8 Magpie
    June 20, 2008

    Hartman, from the comments on the linked page:

    Re: Dry Ice (CO2 ice) vs Water Ice

    In the Martian summer it is much too hot for dry ice to be solid. There is abundant dry ice (frozen CO2)on Mars in the winter. The melting point of dry ice on Mars is -193 F. Today’s weather report from the Canadian weather station on Phoenix shows a low of -112 F — way too hot for dry ice to stay solid right now

  9. #9 S. C. Hartman
    June 20, 2008

    Solid CO2 does not melt to a liquid phase except at high pressure: it sublimates directly to the gas phase. CO2 freezes at -78 C (-108 F), cf. -112 F (-80 C) you cite for the local temp up there (where did the m.p. of -193 F “on Mars” come from? That’s not possible.). The phase transition temp is probably somewhat lower than -78 C at the partial pressure for CO2 in Martian atmosphere, but anyway, it seems to me that solid CO2 could exist below the surface especially if covered by a layer of insulating dust. I look forward to chemical identification of what these evanescent chunks are.

  10. #10 paul orwin
    June 20, 2008

    the melting point you mention is at 1 atm (earth atmospheric pressure – Mars is much lower, so it is in a different part of the phase diagram.

  11. #11 S. C. Hartman
    June 20, 2008

    Check the phase diagram here:
    Liquid CO2 does not exist below about 5 bar ppCO2, either on Mars or on Earth. The ppCO2 on Mars is only about 0.3 bar, so the liquid phase cannot exist at any temperature: only gas and solid. The transition temp at that pressure is about 190 K, or -83 C (-118 F).

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