NASA changes moon crater target

NASA has shifted its moon crater target to Cabeus from the previously targeted Cabeus A in the hunt for hidden water, the space agency stated Monday.

NASA's LCROSS probe and its spent Centaur rocket stage will now aim towards the large crater Cabeus when they slam into the moon on Oct. 9.

By continuously analyzing data from recent moon-watching spacecraft, scientists found that the new target Cabeus has the highest concentration of hydrogen - an indication of possible water ice - than anywhere else at the lunar south pole.


The moon rises over Cairo, September 10, 2009. (Xinhua/Reuters File Photo)
　"NASA's LCROSS team concluded that Cabeus provided the best chance for meeting its mission goals," mission managers said in an announcement.

Scientists announced last Thursday that they had found evidence of water molecules on the surface of the moon.

According to NASA, Cabeus sits at 84.9 degrees south, 35.5 degrees west at the moon's south pole.　It has two nearby satellite craters: the 25-mile (40-km) wide Cabeus A - LCROSS' original target - and Cabeus B, which is about 38 miles (61 km) in diameter.

A small valley etched into the otherwise tall crater ridge of Cabeus should allow sunlight to shine on the ejecta cloud kicked up when LCROSS and its Centaur rocket stage crash into the moon in successive impacts. The shadow of a large hill along the ridge should provide enough contrast for Earth-based measurements of the plume's composition, NASA officials added. 　

"During the last days of the mission, the LCROSS team will continue to refine the exact point of impact within Cabeus crater to avoid rough spots, and to maximize solar illumination of the debris plume and Earth observations," NASA officials said.


　NASA's LCROSS probe - officially known as the Lunar Crater Observation and Sensing Satellite - is a pair of vehicles headed for what maybe one of the most watched cosmic collisions in history. The mission is aimed at the permanently shadowed craters of the moon, where scientists think water ice may exist untouched by the sun's rays.


Data beamed to Earth from LCROSS during the two impacts, as well as observations from a flotilla of spacecraft and telescopes on Earth and in space, will be recorded to determine whether the two vehicles kick up any water ice among the ejecta from their successive crashes.

Source:Xinhua/Agencies