‘Damned close’ asteroid will miss Earth this time, say astronomers

Earth will dodge another interstellar bullet in October, according to the European Space Agency, when an asteroid the size of a house will pass the planet at the relatively near distance of just 44,000km away.

The lump of space rock, which is roughly 25m long and travelling at 14km per second (50,400kph), will pass between Earth and the moon, but will still be 8,000km away from the orbit of geostationary satellites, which circle the globe at a distance of 36,000km.

“We know for sure that there is no possibility for this object to hit the Earth,” Detlef Koschny of ESA’s Near Earth Objects research team told reporters. “There is no danger whatsoever.”

Dubbed 2012 TC4, the asteroid first passed the Earth in 2012, when it was almost twice as far away as it will be this year before disappearing off on its galactic path. It is expected to return at its closest on October 12, having been tracked by the Very Large Telescope of the European Southern Observatory in Chile from a distance of 56 million kilometres away.

“It’s damn close,” said Rolf Densing, who heads up the European Space Operations Centre in Darmstadt, Germany. If it continues to narrow the distance between its orbit and the Earth then the next time it appears in five or so years time, it could strike the planet.

Researchers for the various space programmes across the globe currently have no planetary defence systems in place – they are focused on early warning – and at present ideas of protecting the Earth from an asteroid heading towards it remain in the realm of science fiction.

The ESA said in a statement that 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.”

A 40m-long space rock caused the largest Earth impact in recent history when it exploded over Tunguska, Siberia, in 1908, flattening 2,000 km2 of forest.

Four years ago, 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. It caught everyone unawares.

If an object the size of TC4 were to enter Earth’s atmosphere, “it would have a similar effect to the Chelyabinsk event,” said the ESA.