Don't Panic - but Earth is for another relative close shave.

By most judgements, nearly 20,000 miles is not a near miss. But for an asteroid weighing 130,000 tonnes and circling the Sun at 18,000mph, it is a very near miss indeed.

On February 15, asteroid 2012 DA14 will pass our planet at a distance that lies inside the orbit of many of our communication satellites, although anyone hoping to improve their Valentine’s Day chances by arguing that the 14th could be humanity’s last night on Earth will be disappointed: astronomers are certain that the asteroid will miss. Travelling at five miles per second, it will do so, however, by a margin that is vanishingly small in astronomical terms.

It will, however, certainly be visible if — as is just about possible — it collides with a satellite. Orbiting at 22,000 miles above the equator, geostationary satellites are among the farthest from the Earth. They are placed there so as to have an orbital period of 24 hours, thus making them appear to stay in the same position. Just before 7pm the asteroid will pass through this disk with a small chance of hitting something. At about 8pm it will pass out the other end, its path changed by Earth’s gravity — or by knocking out a TV sports satellite.