Between 16 and 22 July 1994, more than 20 fragments of comet Shoemaker-Levy 9 collided with the giant planet Jupiter. The greatest impact was of the ‘G’ fragment, which exploded with the energy of roughly 600 times the nuclear arsenal of the world, equivalent to six million megatons of TNT.

When fragment ‘A’ plunged into the atmosphere at 60 km/s, the Galileo spacecraft detected a fireball with a temperature of 24,000 K and an associated plume reaching 3,000 km high.