At about 09:20 this morning a meteor exploded over the region of Chelyabinsk, near the southern Ural Mountains of Russia. The resultant fireball and noise caused confusion and even shattered windows in some places. Some reports say around 500 people were injured by its effects.

It is thought that the meteor was about 40 tonnes and 15 metres across, when it entered the atmosphere. That makes it about one third the size of Asteroid 2012 DA14, which will make an unusually close approach to the Earth in a few hours time, as it skims passed us within the orbits of our own satellites.

It’s a timely reminder of the fact that although we can track many Near Earth Objects (NEOs), we’ll never spot them all.