Water Ice Found on Moon’s North Pole


It’s no longer a question of if there is water on the Moon; now it is how much. Scientists using the Mini-SAR instrument on India’s Chandrayaan-1 spacecraft have detected water ice deposits near the moon’s north pole. Mini-SAR, a lightweight, synthetic aperture radar, found more than 40 small craters with water ice. The craters range in size from 2 to15 km (1 to 9 miles) in diameter. Although the total amount of ice depends on its thickness in each crater, it is estimated there could be at least 600 million metric tons of water ice.

“The emerging picture from the multiple measurements and resulting data of the instruments on lunar missions indicates that water creation, migration, deposition and retention are occurring on the moon,” said Paul Spudis, principal investigator of the Mini-SAR experiment at the Lunar and Planetary Institute in Houston. “The new discoveries show the moon is an even more interesting and attractive scientific, exploration and operational destination than people had previously thought.”

During the past year, the Mini-SAR mapped the moon’s permanently-shadowed polar craters that aren’t visible from Earth. The radar uses the polarization properties of reflected radio waves to characterize surface properties. Results from the mapping showed deposits having radar characteristics similar to ice.

Fresh crater, Main L, 14 km diameter, 81.4° N, 22° E. Credit: NASA

“After analyzing the data, our science team determined a strong indication of water ice, a finding which will give future missions a new target to further explore and exploit,” said Jason Crusan, program executive for the Mini-RF Program for NASA’s Space Operations Mission Directorate in Washington.

The results are consistent with recent findings of other NASA instruments and add to the growing scientific understanding of the multiple forms of water found on the moon. Previously, the Moon Mineralogy Mapper discovered water molecules in the moon’s polar regions, while water vapor was detected by NASA’s Lunar Crater Observation and Sensing Satellite, or LCROSS.

Mini-SAR and Moon Mineralogy Mapper are two of 11 instruments on Chandrayaan-1. The Mini-SAR’s findings are being published in the journal Geophysical Research Letters.

Source: NASA

12 Replies to “Water Ice Found on Moon’s North Pole”

  1. Same as it ever was.

    Wonder if these announcements will help revive the lunar exploration program?

  2. There is a difference between believing something to be so and confirming it. For that reason this is important and excellent news.

    I doubt the news will affect the near-term plans to move towards a return to the Moon (sadly), but long term this can only be good news for the prospects of a permanent presence on the Moon.

    We still have to figure out how accessible it is, and how best to exploit it, but I am sure those questions will be answered in time.

  3. A quick burst of mental arithmetic yields this:
    6 E12 kg of water
    6 E9 m2 of crater area (really roughly)
    1000 kg/m3 density
    ==> 1 m thickness.on all of the area.

    Are they saying that all these craters are covered with 1 m of ice? I don’t think so.

    This is not the first (or last, I suspect) water on the moon announcement that just doesn’t add up. (remember the “water everywhere” announcements)

    I sense politics.

  4. oh I see….

    A competing site says: “… bla bla 1.3 million pounds (600 million metric tons) of water ice”

    I hate to be the party crasher, but 1.3 E6 pounds is 0.6 tons, not 600 million tons… Only 9 orders of magnitude of difference.

    So a layer of 1 nm, not 1 m – more like it. a molecular monolayer, as one would expect on a cold vacuum chamber.

    I don’t know which numbers are right, but I wish someone would pay attention.

    The LCROSS impact liberated some 100 kg of water. Not sure where this fits, since that was a direct hit on to the best possible target.

    I found this: http://www.spaceagepub.com/pdfs/Shevchenko_1.pdf
    which puts a lower estimate on the amount of shaded area, and also says the shading goes away every several years, so there’s no “billion of years of accumulation” as I’ve heard in other releases.

    Let’s see what they announce tomorrow.

  5. ok – I was off too – 600 tons, not 600 kg.

    Fine – but I caught my own mistake :).

    And, this is more consistent with the LCROSS result.

    So the two numbers are only 6 orders of magnitude off…

    And, I now know which number to bet on – the 1.3E6lbs, not the 600E6 tons, which means the source numbers were not even metric. sigh.

    The layer is thus in the um range, to an order of magnitude, depending on the real area it occupies. My guess is that it is still a monolayer, but spread out (as monolayers do) on the physical micro-surface area, which in the case of regolith, is much larger than the geometrical area.

  6. CrazyEddieBlogger: I’d imagine that things on the north pole are similar to those on the south pole. On the south pole they weren’t saying that there was a layer of pure water ice, but rather that there was a small amount of water ice mixed in with the regolith.

    The figures I saw indicated that the regolith on the south pole had approximately the same concentration of water per unit volume as dried, set concrete.

  7. WOW! A whole new moon! WATER rights anyone?

    Next up, how to operate Mercury filtration systems in 1/6 G. That means you have to use horizontal centrifuges, right?

  8. Gopher – sounds about right, though I’m not a concrete expert… It turned out, based on estimating the amount of rock ejecta from the impact, to be 10-100 ppm.

    It’s interesting from a scientific point of view, but what’s yanking my chain are all those inferences that this is good for use by exploration, since now we can get water on the moon.

    It’s a pattern – many of these PRs have such misleading statements in them. I know some folks want to have a lunar base really bad, but this sort of PRs is not the way to go about it.

  9. CrazyEddieBlogger:

    I don’t know which numbers are right, but I wish someone would pay attention.

    Dude, it looks like you’re the one who did not pay attention… 😉

    If you will check again at the NASA site, it actually states (emphasis mine):

    Although the total amount of ice depends on its thickness in each crater, it’s estimated there could be at least 1.3 trillion pounds (600 million metric tons) of water ice.

    That’s trillion (10^12), not “million”; therefore, the quoted figure of (approximately) 600 million metric tons is correct. 🙂

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