LRO/LCROSS launched

Unmated LRO/LCROSS at Cape Canaveral Air Force Station
Unmated LRO/LCROSS at Cape Canaveral Air Force Station

The Lunar Reconnaissance Orbiter (LRO) and the Lunar Crater Observation and Sensing Satellite (LCROSS) have been successfully launched and are on their way to the Moon. Both will take four days to reach the Moon, after which the LRO will settle into a polar orbit and start taking detailed maps of the Moon over a period of a year. More pretty pictures from the Moon!

However, LCROSS will not crash into the Moon after the four days: instead, it will use the Moon as a gravitational assist to enter a very large orbit around the Earth. This is so that the impact can occur at a high angle rather than the shallow angle that it would crash with if it were to impact the Moon directly. Of course, LCROSS won't be crashing into the Moon by itself: it will first observe a much larger impact at the lunar south pole caused by the upper stage of the rocket that launched LRO and LCROSS, which will soon be followed by a much smaller impact from LCROSS itself. The impact will occur sometime in October, and with any luck, we might get definite confirmation of water deposits on the Moon.