The European Space Agency's SMART-1 spacecraft took this image of the Hadley Rille on the south-east edge of Mare Imbrium on the Moon. The bright bumps on the lower part of the image are the Appenine mountains, which formed a backdrop during the Apollo 15 mission in 1971. The Hadley Rille is a 120 km (76 mile) long gully - probably a collapsed lava tube - that formed about 3.3 billion years ago.