An asteroid which is to pass Earth will be used by Nasa to conduct tests on a planetary defence system.
The rock, which has been called 2012 TC4, is to pass the planet on October 12 at a distance of 6,880 kilometres - which is actually relatively close.
TC4 measures 30 metres across, and while it will not directly hit Earth, Nasa will use the opportunity presented by the fly-by to conduct a series of tests.
Researchers will use its presence to test current measures for detecting, tracking, and responding to potential asteroid threats.
One of the proposed ways of removing asteroids on potential collision courses with the plane is to fire a ship directly at them. However nothing will be fired at the asteroid as it whizzes past the earth this time, as the system won't be ready until 2022.
The space agency says its Double Asteroid Redirection Test (DART) spacecraft will be ready for full tests on another asteroid flyby in 2022.