Moon crash: the search for water

The American space agency, Nasa, says two unmanned spacecraft have crashed into the moon as planned in an experiment seeking evidence of water.

However, live pictures of an expected plume of debris failed to materialise.

A rocket was steered into a crater near the lunar south pole at a speed of 8,000km/h, followed by a satellite probe equipped with cameras and other instruments.

The probe was designed to analyse debris thrown up by the impact, and send the results back to Earth, before it too crashed into the moon.

Planetary scientist Professor Colin Pillinger explains.

First broadcast 9 October 2009