An asteroid the size of a house will be watched carefully by astrophysicists as it hurtles “damn close” to Earth today.
The large space rock, named 2012 TC4, was initially spotted five years ago by the Pan-STARRS telescope at the Haleakala Observatory, in Hawaii, before disappearing as it orbited the Sun.
After that, it re-emerged in July on the trajectory well within our lunar orbit.
Researchers have said the asteroid is on course to move safely by, just south of Australia and poses no risk.
However, it presents space agencies with a rare chance to test the planet’s space defenses and wargame what they might do if a more substantial, more dangerous asteroid was discovered heading directly for Earth.
HTC4 is between 50 to 100ft in diameter and traveling through space at roughly 26,000kmh – 7km a second. It is believed to begin to pass Globe from around 7 is GMT today and will be about 43,000km from our atmosphere.
This may appear to be quite a distance away, yet it’s a short distance in planetary terms and around one-eighth of the distance between the Earth and the Moon.
Rolf Densing, who heads the European Space Operations Centre in Darmstadt, Germany said:
“It’s damn close. The farthest satellites are 36,000km out, so this is a close miss.”
Earth has been struck by asteroids and meteors repeatedly over its 4.5 billion-year lifespan.
The most well-known event was the 95km-wide asteroid that hit the coast of Mexico around 65 million years back, resulting in the extinction of the dinosaurs.
But there were newer, less dramatic examples.
The largest recorded asteroid incident is the 1908 Tunguska event in Russia.
A fireball thought to be between 160ft and 330ft wide incinerated around 19,00sqkm of forest within an area of remote Siberian forest close to the Podkamennaya Tunguska river.
Residents in the nearest town, 55km away, apparently felt the heat from the blast.