The sensitive infra-red detectors of the Keck Telescope on Mount Mauna Kea in Hawaii were almost saturated by the signals received from fragment G, the largest yet to collide with Jupiter, a spokesman for Nasa, the United States space agency said yesterday.
'The signals were absolutely spectacular. The image of the impact became as bright as Jupiter itself.' Scientists estimated that fragment G was about 3km across, he said. Astronomers have been overwhelmed by the size of the impacts. They had feared that the 21 fragments of the comet would spilt into further pieces before crashing into Jupiter's frozen atmosphere making the collisions difficult to see from Earth.
Imke de Pater, an astronomer at the Keck Observatory, said: 'The plume from fragment G just overwhelmed anything we had seen before. It's truly, truly remarkable.'
Eugene Shoemaker, a scientist at the US Geological Survey and co-discover of the comet, said: 'If (the much smaller) fragment A had hit North America, it's likely it would have made a crater 20 kilometres (12 miles) in diameter.' He estimated that the energy released by fragment G was equal to about 250 million megatons of TNT - equivalent to about 12 billion Hiroshimas - and created temperatures of more than 16,600C. 'The energy released is beyond our experiences on Earth,' said Lucy McFadden, a University of Maryland astronomer.
A giant piece of the comet even larger than fragment G is expected to hit the planet tomorrow.