Sep 25 2009
If not, you’ve got only a couple more weeks. NASA says LCROSS — the Lunar CRater Observation and Sensing Satellite — will be a “smashing success” on October 9! (Sorry, couldn’t resist that one, but I promise to avoid impact-related puns from here on…)
Water on the Moon is big news today. For example, NASA’s Moon Mineralogy Mapper (M3), that hitched a ride almost a year ago onboard India’s Chandrayaan-1 spacecraft, discovered both water and hydroxl molecules especially in the lunar polar regions (Science, September 24, 2009). According to Jessica Sunshine of the University of Maryland,
“Our analysis unequivocally confirms the presence of these molecules on the Moon’s surface and reveals that the entire surface appears to be hydrated during at least some portion of the lunar day.”
Although water and hydroxyl are present in larger abundances than expected and are a very exciting discovery, the actual water molecule fractions are only about 1000 ppm of lunar soil. Apparently hydrogen ions in the solar wind arriving at the lunar surface interact during the day with oxygen-rich minerals near the lunar surface to produce the observed water.
Regarding the M3 lunar surface water discovery, Carle Pieters of Brown University cautions that,
“When we say ‘water on the Moon,’ we are not talking about lakes, oceans, or even puddles. Water on the Moon means molecules of water and hydroxyl that interact with molecules of rock and dust spacifically in the top millimeters of the Moon’s surface.”
Of course, the lost lunar lakes (or even oceans) would be the most important and cost-effective resource we could find on the Moon — the holy grail for lunar scientists and others interested in studying, developing, and colonizing the Moon. Active international interest in lunar polar waters is consistent with accelerating human expansion into the cosmos as we approach the 2015 Maslow Window.
To detect these types of major water deposits on the Moon — suggested previously by Clementine (1994) and Lunar Prospector (1999) — NASA has developed LCROSS that will impact a Centaur upper stage at 2.5 km/sec on the Moon and create an ejecta cloud expected to expand 10+ km above the surface.
In a previous post, India and NASA Search for the Lost Lunar Lakes, you may want to check out my interview with Lunar Prospector PI Dr. Alan Binder as well as the challenging comments of two other lunar scientists, Drs. Paul Spudis and Stewart Nozette.
LCROSS is not exactly a subtle technique but it should meet our basic needs. On October 9, after venting any remaining fuel from Centaur, it will will impact the Moon, excavating at least 200 tons of lunar rock and soil. The Shepherding Spacecraft will rapidly descend into the plume making in situ measurements of its composition — searching for lunar water — and transmiting this data back to Earth, just before it creates a second impact plume on the Moon.
Funseekers on Earth — amateur astronomers and students — with 10″ or larger telescopes may be able to see the plume and participate in the discovery! Many public events are planned around the country or you can watch from the comfort of your video room at home on NASA TV. NASA also provides impact timing for those planning their own LCROSS Impact Party. See this link and have a blast!