On 28 June 1911 an explosion erupted in the sky over the Nakhla region of Alexandria in Egypt.

A chunk of rock, about the size of a football, had broken away from the surface of Mars several million years ago.

It floated around the Solar System until eventually the Martian rock was pulled into our planet's gravitational field.

When it fell to Earth a century ago, eyewitnesses saw an explosion high in the atmosphere, as the meteor split into dozens of fragments which hurtled towards them and were buried up to a meter deep in the ground.

Dr Marek Kukula, Public Astronomer at the Royal Observatory Greenwich, looks at the legacy of the Nakhla meteorite.

These precious rocks are now being used by scientists to ground-truth data sent back from Spirit and Opportunity - the two rovers currently exploring the Martian surface.

Producer: Michelle Martin