An asteroid the size of a house will pass very close to Earth later this month, giving scientists a chance to try out their planetary defence system.
The asteroid, known as 2012 TC4, was first spotted by the Pan-STARRS observatory in Hawaii in 2012, but its orbit meant that it could not be tracked.
Early observations indicated that it could come as close as 4,200 miles from the Earth’s surface – well within the ring of geostationary satellites – on October 12.
However, new observations by the European Southern Observatory’s Very Large Telescope in Chile reveal that it will miss our planet by 27,000 miles – roughly one-eighth of the distance to the Moon – which is still very close in astronomical terms.
The asteroid is estimated to be between 30 and 100 feet (10 to 30 metres) in size, and is travelling at about 30,000 mph (14 kilometres per second).
If an asteroid of this size was to enter our atmosphere, it would have a similar effect to the Chelyabinsk meteor, which exploded in an air burst over Chelyabinsk Oblast, Russia, in February 2013.
The meteor generated a bright flash and produced a hot cloud of dust and gas. The bulk of the object’s energy was absorbed by the atmosphere, but some eyewitnesses felt intense heat from the fireball.
Scientists plan to use the close flyby of 2012 TC4 as an opportunity to test out their planetary defence system, in preparation for a real asteroid threat.