One was going to Saturn and another is en route to a comet. But both used spectrometers during lunar fly-bys for casual looks with spectacular results.
We have suspected for a while, that ice might exist in deep polar craters where the sun never shines. But this new data will rewrite the science books.
"This was thought to be impossible to find water on the surface of the moon, in hot sunlight, at the equator. This is sensational," said Cassini Mission Investigator Roger Clark.
NASA has discovered traces of water in so-called dry areas where Apollo astronauts walked. Not a lot of it, maybe just a few molecules, but they're right on the surface and they seem to move around and nobody knows why.
"Is it mobile or is it being created or destroyed on a rapid matter. We don't know these issues. It's intriguing," said Brown University mineralogist Carle Pieters.
Scientists have known for a long time that water exists in space. There is enough that molecules hit and stick to deep space satellites and it's enough to even skew their instruments.
But this lunar water is a major discovery. It's an implication that the lifeblood for biology on earth suddenly seems to be everywhere, though not necessarily in large quantities.
"About a quart or liter of water per ton of lunar material and that is lunar material on the top part of the surface," said Clark.
For Dr. Tony Colaprete at NASA Ames in Mountain View, the timing of this announcement could not be better. On October 9th, his L-Cross mission will crash two spacecraft into dark, polar craters, where NASA hopes to find enough frozen water to support men, and make rocket fuel for longer, future trips.
"We are hopeful for the big mother lode -- a geyser coming out of our impact. By geyser, I mean a subtle percent of water, that is something greater than what they see in these observations," said Dr. Colaprete
If you press him, Dr. Colaprete suspects that there is enough water spread around the moon to fill Lake Erie and relatively speaking, that's not a lot of water.
Even the wettest piece of lunar real estate would be much drier than any desert on earth and even so, this is a game changer.