The asteroid will zoom past at a distance of about 27,300 miles, which is an eighth of the distance from the Earth to the Moon, according to the European Space Agency. This is just far enough away to miss satellites which orbit at about 22,000 miles above Earth. Luckily, it looks that humanity will live to fight another day because the asteroid will not whack into our planet.
The asteroid is dubbed 2012 TC4 and first flitted past our planet in October 2012 at about double the distance before disappearing from view. It is between 15 and 30 metres long and was travelling at a speed of about nine miles per second when spotted.
“We know for sure that there is no possibility for this object to hit the Earth,” Detlef Koschny of ESA's research team told AFP. “There is no danger whatsoever.”
Scientists expected the asteroid to return for a near-Earth rendezvous this year but did not appreciate quite how close it would come. Now, the Very Large Telescope of the European Southern Observatory (ESO) in Chile has managed to track the rock down and determine its trajectory.
“It's damn close,” said Rolf Densing, who heads the European Space Operations Centre in Darmstadt, Germany. “The farthest satellites are 36,000 kilometres out, so this is indeed a close miss.”
Asteroid 2012 TC4 appears as a dot at the centre of this image from ESOs Very Large Telescope
For researchers, the near miss will provide a rare chance to test Earth's "planetary defence" systems - which at this point are focused on early warning rather than active asteroid deflection. Observing TC4's movements "is an excellent opportunity to test the international ability to detect and track near-Earth objects and assess our ability to respond together to a real asteroid threat," said an ESA statement.
A 40-metre space rock that was slightly bigger than TC4 caused the largest Earth impact in recent history when it exploded over Tunguska, Siberia, in 1908. In 2013, a meteoroid of about 20 metres exploded in the atmosphere over the city of Chelyabinsk in central Russia with the kinetic energy of about 30 Hiroshima atom bombs. The resulting shockwave blew out the windows of nearly 5,000 buildings and injured more than 1,200 people.
If an object the size of TC4 were to enter Earth's atmosphere, "it would have a similar effect to the Chelyabinsk event," ESA said. There are seven terrifying ways that asteroids could wipe out life on Earth. The Perseid meteor shower will hit the UK this weekend, causing up to 80 shooting stars to burn through the sky every hour.