The collision between


a rogue comet and Jupiter is quickly unfolding as a fierce and sobering celestial catastrophe, astronomers around the world have reported.


The Keck Telescope in Hawaii captured images of two comet fragments exploding into giant, gaseous fireballs hotter than the surface of the sun. The Hubble space telescope photographed a 4,166-kilometer-wide mushroom cloud erupting hundreds of kilometers into space from a detonation more powerful than any nuclear weapon on Earth.


"We are all flabbergasted at what we are seeing," said planetary scientist Heidi Hammel, who is leading the team of scientists gathered in Maryland to analyze the images taken by NASA's space telescope. "We can be very glad that this comet was heading for Jupiter and not Earth."


It is the first time humanity has seen a comet hit a planet, though many planetary experts believe that Earth -- like the other planets in the solar system -- has been hit thousands, if not millions of times in eons past.


Another 14 major pieces of the shattered comet Shoemaker-Levy 9 are expected to hit by Friday.


The smallest fragment to hit so far -- a kilometer-wide ball of compacted ice and rock that struck Jupiter on Saturday -- released so much explosive energy that on Earth it would have vaporized a city the size of Los Angeles in an instant, comet scientists said. At the same time, it would hurl enough dust and debris into the upper atmosphere to dangerously disrupt the world's climate, they said.