Water on the Moon

Yup, the LCROSS crash did kick up some water.
NASA shows proof.


UV-spectroscopy shows H2O vapour.
About 0.1 m3 from a ~ 10m radius crater.

Not much, but definitely there.

I must day, the LCROSS “bombing” of the Moon is one of the worst handled NASA events in a long time, from a press perspective – very poor explanation of why NASA did this when it did, the likely scale of the event or indeed the analysis.

Lunar orbits are generally unstable – chunks of metal going around the Moon will generally end up crashing into the Moon – this is partly due to the Earth’s gravity perturbing orbits, and partly due to the Moon’s intrinsic lumpiness.
The issue with the LCROSS upper stage was to choose the time and location of the Moon impact to get something out of it – in this case the spectroscopy of the impact plume and the secondary plume.
Lunar impacts happen all the time, but they are transient events, so generally instruments are not targeting the impact as it happens. Hence the benefit of knowing when even a small impact happens, in advance.

The impact was small – there was no chance ever of a huge glowing mushroom cloud visible in amateur class telescopes, I did not get up to watch the event because I knew there would be nothing to see. The Moon’s potential well is shallow and the upper stage is low mass as these things go.

The spectral analysis takes time, there was very little chance of “‘live” results, the main issue is whether there would be no water, or a tiny bit – 100 liters from a 10m radius crater is dry, by Earth standards. The amazing thing is that there is any water at all.

So, cool result, terrible public relations.

NYT story

NASA press release


  1. #1 Gino
    November 13, 2009

    STRANGE ANOMALY DISCOVERED ON MOON IN NASA PHOTO… Buzz Aldrin comments on the “Monolith” on Mars Moon Phobos… APOLLO 11 UFO… VIDEO: “I Saw Structures on the Moon”:

  2. #2 solid wood furniture
    November 16, 2009

    If there is really water on the moon, I think it is not the same water we have here on Earth.

  3. #3 Nova
    November 17, 2009

    I honestly dont believe that there is water under the lunar surface, how can water exist without atmosphere? there must be a catch in this story.

  4. #4 Ixu
    November 17, 2009


  5. #5 Lab Lemming
    November 18, 2009

    Is there a paper, or is this cold-fusion style wad shooting?

  6. #6 Arunav
    November 18, 2009

    The earlier Chandrayaan claim based on 3 micron absorption was announced only after it was accepted by Science (along with papers that went back and confirmed it in Cassini and Deep Impact)


    This, as Steinn points out was badly handled PR wise. And once they dug that hole I suppose they had to put out a press release relatively quickly to say that it worked.

New comments have been temporarily disabled. Please check back soon.