The European Space Agency (Esa) says its comet lander, Philae, has woken up and contacted Earth.

Philae, the first spacecraft to land on a comet, was dropped on to the surface of Comet 67P by its mothership, Rosetta, last November.

It worked for 60 hours before its solar-powered battery ran flat.

The comet has since moved nearer to the Sun and Philae has enough power to work again, says the BBC’s science correspondent Jonathan Amos.