NASA will today crash an unmanned 2.2 tonne rocket into the surface of the moon in an effort to detect the presence of ice and water.
The LCROSS (Lunar Crater Observation and Sensing Satellite) mission, costing in the region of £50 million, will consist of a large Centaur rocket and a following probe hitting the lunar surface at roughly twice the speed of a bullet.
Expected to hit the moon at 12:31 BST, the Centaur rocket is designed to create a crater in the moon's surface - throwing up an estimated 350 metric tonnes of debris some 6.2 miles into the air. Shortly after, the LCROSS mothership will pass through the debris and use onboard spectrometers that "analyse the sunlit plume for signs of water, water fragments, salts, clays, hydrated minerals and assorted organic molecules".
The mothership itself will then strike the lunar surface roughly four minutes after the Centaur rocket's collision, creating a smaller plume of debris for analysis by hundreds of telescopes.
The Centaur rocket and LCROSS mothership were launched as one from Cape Canaveral, Florida, back in June, and separated in the early hours of the morning. On its official Twitter channel, LCROSS stated "Good bye Centaur. Thanks for an interesting ride. Now go do good work & kick up some dirt!"
NASA expects the impact and debris plumes to be visible to amateur astronomers, stating that viewers with mid-sized telescopes (10in or larger) should be able to see the action from Earth.
Viewers are advised to focus on the Moon's south pole, where LCROSS will be targeting a crated known as Cabeus. However, the event will be best visible to viewers across parts of the United States, where it will still be dark. Hawaii is the best place to be, with Pacific coast states of the USA a close second, says NASA.
Web-users wanting to watch the event online can do so via NASA TV.