The Lunar Reconnaissance Orbiter has been spending the past months calibrating its instruments since its launch in June. Its camera works best at an altitude of 50 kilometers, but it takes fuel to maintain such an orbit, so the orbiter has been spending its time in a commissioning phase orbit while it calibrates its instruments. The commissioning phase is now over, and the LRO has executed a 3 minute burn to put itself into a polar orbit 50 kilometers above the Moon, where it will spend the next year taking images of the surface and studying the Moon.
The LRO has already given us pictures of the Apollo landing sites and other locations on the Moon during its commissioning phase, but it should give us even better pictures now that it is officially in business.
LCROSS, the Lunar Crater Observation and Sensing Satellite launched in June, will be crashing into the Moon next month. And now we know exactly where it will crash into the Moon. The upper rocket stage that launched LCROSS will be crashing into the permanently shadowed parts of the crater Cabeus A near the Moon's south pole, which will kick up a huge plume that LCROSS will observe. And it will be soon followed by the crash of LCROSS itself, which will kick up a smaller plume that telescopes on Earth could observe.
With any luck, there will be water in the permanent shadows around the Moon's south pole, and LCROSS will be able to definitely confirm its presence.
The Lunar Reconnaissance Orbiter has just entered lunar orbit! Now that it is in orbit around the Moon, it should take about a couple of months to settle into its final polar orbit 50 kilometers above the surface. Once it settles into its final orbit, the LRO should be spending at least a year making detailed maps of the surface of the Moon (among other things).
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.