It’s not a mirage, it may actually be an oasis. From The New York Times:
The Moon, at least at the bottom of a deep, dark cold crater near its south pole, seems to be wetter than the Sahara, scientists reported Thursday.
In lunar terms, that is an oasis, surprisingly wet for a place that had long been thought by many planetary scientists to be utterly dry.
If astronauts were to visit this crater, they might be able to use eight wheelbarrows of soil to melt 10 to 13 gallons of water. The water, if purified, could be used for drinking, or broken apart into hydrogen and oxygen for rocket fuel — to get home or travel to Mars.
“That is a very valuable resource,” said Anthony Colaprete, principal investigator of NASA’s Lunar Crater Observation and Sensing Satellite — or Lcross, for short — which made the observations as it, by design, slammed into the Moon a year ago.