First-ever comet material discovered on Earth
A comet exploded over Egypt 28 million years ago, leaving behind a "mysterious" black pebble - the first-ever comet material found on Earth, scientists said on Tuesday as they announced the discovery. "Comets always visit our skies - they're these dirty snowballs of ice mixed with dust - but never before in history has material from a comet ever been found on Earth," said professor David Block at South Africa's University of the Witwatersrand.
South African scholars headed a team of geoscientists, physicists and astronomers who tested the pebble, which was found in 1996. The 30-gramme pebble had a clear "extraterrestrial component" yet was distinctly different from meteorites, said professor Jan Kramers.AFP