Physicist says aliens could be watching us through a space rock
A physicist has suggested that aliens may have, at some point in history, planted a surveillance device on a nearby space rock.
Dr James Benford made the startling claim in the Astronomical Journal.
He believes that extraterrestrial life may have spotted the evolution of humans thousands of years ago, and placed robotic 'lurkers' on an asteroid to keep an eye on our progress.
His theory also reveals his belief that these alien civilisations may still be listening in, and he's come up with some ideas on how we can make contact with them.
Find out more in the video above.