A small flash illuminated the lunar surface as the European Space Agency's (ESA) unmanned SMART-1 spacecraft crashed into the near side of the moon in the "Lake of Excellence" region at about 4,500 miles per hour.

The spacecraft, a cube measuring around a meter on each side, tested new space technology during its three-year mission, and has spent the last 16 months observing the moon and gathering information on its composition.

"The measurements by SMART-1 call into question the theories concerning the moon's violent origin and evolution," SMART-1 project scientist Bernard Foing said on ESA's Web site.

The moon may have formed from the impact of a Mars-sized asteroid with the Earth 4.5 billion years ago, ESA said.

"SMART-1 has mapped large and small impact craters, studied the volcanic and tectonic processes that shaped the moon, unveiled the mysterious poles, and investigated sites for future exploration," Foing said.

The spacecraft, which weighed 807 pounds, carried a miniaturized imaging camera, an X-ray telescope and an infrared spectrometer to seek out minerals.

SMART-1 also tested new deep-space communication techniques for spacecraft and techniques to achieve autonomous spacecraft navigation. Scientists will now begin analyzing the mass of data acquired by the spacecraft.

"The legacy left by the huge wealth of SMART-1 data, to be analyzed in the months and years to come, is a precious contribution to lunar science at a time when exploration to the moon is once again getting the world's interest," said Foing.

NASA is planning a manned mission to the moon for 2020 at the latest.