Astronomers have captured the moment a lump of rock slammed into the moon with so much force that the bright flash could be seen from Earth with the naked eye.

The 400kg (63st) meteorite, travelling at 61,000 km/h (40,000 mph), punched a fresh crater on the moon's surface some 40 metres wide in what is thought to be the largest lunar impact ever recorded.

The rock, which was about a metre in diameter, ploughed into an ancient lava-filled basin called the Mare Nubium, producing a flash almost as intense as the Pole Star that took more than eight seconds to fade.

The impact energy was equivalent to 15 tonnes of TNT – at least three times as great as that from the previous record-holding lunar impact, observed by Nasa in March last year.

It's a simple matter of one type of energy being converted into another. All that kinetic energy has to go somewhere.