A house-sized asteroid whizzed past Earth on Thursday 12 October at a close, but safe, distance of approximately 26,000 miles. This is just above the distance that a lot of communication satellites orbit the planet.
Asteroids are rocky objects that orbit the Sun. Although hundreds of asteroids, small and large, pass by Earth every ry year, this one, called 2012 TC4, was particularly important. This is because Nasa, the US space agency, used the asteroid to test the global asteroid pre-warning system. Observatories, science labs and universities around the world are involved in the pre-warning project.
Michael Kelley, a scientist who is part of the project, says:“Asteroid trackers are using this fly-by to test the worldwide asteroid detection and tracking network, assessing our capability to work together in response to…