Sleeping space probe to wake up
A sleeping space probe called Rosetta will be reactivated today as part of a daring mission to land on a comet.
Rosetta was launched in 2004 but was put into hibernation in 2011 to save power.
The craft is so far away from the Sun that its solar panels could not have kept it running.
The probe should wake up at 10am today and should send a signal to Earth this afternoon if all its systems are working.
Rosetta is due to drop a lander on Comet 67P/Churyumov-Gerasimenko on 11 November.
Comets are believed to contain materials that have remained largely unchanged since the formation of the Solar System 4.6billion years ago.
Jean-Jacques Dordain from the European Space Agency said: "Rosetta is a unique mission... comets may be at the origin of who we are."