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NASA's $73 Million Water-Finding Trick
An anonymous reader writes "The folks at NASA, obviously looking for new ways to explore the universe, are planning to crash a two-ton probe into the moon. The goal? To find water." From the article: "NASA plans a series of robotic precursor missions including the Lunar Crater Observation and Sensing Satellite, or LCROSS, which will plow into the crater, and the mapper, called the Lunar Reconnaissance Orbiter. When LCROSS strikes the crater, it is expected to create a hole 16 feet deep and send up a 2.2 million-pound (998,000-kg) plume of debris for sensors and cameras stationed on a second spacecraft to monitor. Dozens of ground-based telescopes, as well as possibly space observatories, such as the Hubble telescope, will be trained on the plume as well."
They used to crash the upper stages of the Saturn 5 to gain scientific data from the Moon. Learned a lot that way.
Hard to say if this will work though. The theoretical plume size has a lot of unknowns involved. To date, they have never directly observed water on the Moon, but have only identified a certain amount of hydrogen, which would correspond to a certain amount of water, if that hydrogen was bound in water molecules. If the hydrogen is hydrated minerals, that plume will be much, much smaller than projected.
"... it is expected to create a hole 16 feet deep and send up a 2.2 million-pound (998,000-kg) plume of debris"
I think they're most likely ballpark figures for a 5 metre deep crater, and 1000 tonnes of debris. Convert these to imperial measurements and back again without thinking too much, and you gain many significant figures of accuracy!
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NASA tried this impact project with Lunar Prospector in 1999. But it did not lead to any substantial ejection of water vapor off the impact point. No water vapor was observed with the Hubble/STIS (spectrograph). I believe (have not RFTA) that NASA wants to do it right with a proper impactor at this time.
Is this maybe what you're referring to? From the linked article:
There is also a very old historical account that could also be explained by a meteor hitting the Moon. This was recorded by Gervase of Canterbury who, in 1178, along with five other monks, saw a very bright flash on the Moon:
"There was a bright New Moon, and as usual in that phase its horns were tilted towards the east. Suddenly, the upper horn split in two. From the midpoint of the division, a flaming torch sprang up, spewing out fire, hot coals and sparks."
Some astronomers believe that the crater Bruno, one of the youngest on the lunar surface, may have been formed in this event.
More information in this article. Hope this helps.
The higher the technology, the sharper that two-edged sword.