Scientists are to send two spacecraft to knock an asteroid off course, as part of a practice for what they would do if a rock was threatening the future of humanity. The joint US-European Aida (Asteroid Deflection & Assessment) mission will send a small spacecraft to crash into the egg-shaped rock, known as Didymoon. That asteroid doesn’t pose any threat to us — and is far too small to do so — but the mission will be important test for...

Kiefer Sutherland has confirmed he will "definitely not return in any way" to his hit TV show, 24. Sutherland starred as counter-terrorism agent Jack Bauer in the highly-successful thriller from 2001 to 2010, and made a return in last year's spin-off series 24: Live Another Day. When Fox announced a reboot with a new protagonist earlier this year, the star said he hadn't "ruled out a cameo."