The Moon could have been formed from a giant impact

The Smart 1 lunar probe is trying to solve the mystery of how the Moon was born billions of years ago.

Manuel Grande, of Aberystwyth University, said one theory was that it was formed from debris from Earth.

Smart 1 will crash into the Moon's surface on 3 September, bringing to an end a three-year research project.

Launched in 2003, it was the beginning of an exploration voyage by the European Space Agency.

Sending back details and pictures for about 18 months, the craft has been producing an X-ray map in an attempt to deduce precisely how the Moon was made.

Apollo missions

Now scientists will start to analyse the data it has sent back.

Professor Manuel Grande with a model of Smart 1

Professor Grande, of the university's Institute of Mathematical and Physical Sciences, said the Moon had become "sexy" again.

"Over the next few years Japan, China, India and the United States will send exploratory probes to the moon ahead of planned manned mission," said Prof Grande.

He said the six Nasa Apollo missions and three unmanned Soviet Union lunar landings only investigated a small portion of the Moon, which has a surface roughly the size of Africa.

"It eventually dawned on experts a few years ago that there was more to the Moon. Over the last decade there have been two similar information-gathering missions," he said.

There are a few theories about how the Moon was formed.

One is that a Mars-sized object smashed into the juvenile Earth billions of years ago, flinging up debris which later merged to form the Moon.