Asteroid to shave past Earth on October 12

— A house-sized asteroid will shave past our planet on October 12, far inside the Moon’s orbit but without posing any threat, astronomers said on Thursday.

The space rock will zoom by harmlessly at a distance of about 44,000km — an eighth of the distance from the Earth to the Moon, according to the European Space Agency. This is just far enough to miss our geostationary satellites orbiting at about 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 said. “There is no danger whatsoever.”

The asteroid, dubbed 2012 TC4, first flitted past our planet in October 2012 — at about double the distance — before disappearing from view. It is about 15-30 metres long, and was travelling at a speed of some 14km per second when spotted.

Scientists expected the asteroid to return for a near-Earth rendezvous this year, but did not know how close it would get.

Now, the Very Large Telescope of the European Southern Observatory (ESO) in Chile has managed to track the rock down, some 56 million kilometres away, 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 36,000km out, so this is indeed a close miss,” he said.

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. Asteroids are rocky bodies left over from the formation of our solar system some 4.5 billion years ago.

There are thought to be millions of them, most of them in a “belt” between the orbits of Mars and Jupiter.