Author: Or Graur, Associate Professor of Astrophysics, University of Portsmouth

The European Space Agency has given the go-ahead for initial work on a mission to visit an asteroid called (99942) Apophis. If approved at a key meeting next year, the robotic spacecraft, known as the Rapid Apophis Mission for Space Safety (Ramses), will rendezvous with the asteroid in February 2029. Apophis is 340 metres wide, about the same as the height of the Empire State Building. If it were to hit Earth, it would cause wholesale destruction hundreds of miles from its impact site. The energy released would equal that from tens or hundreds of nuclear weapons, depending on the…