65 million years ago a huge cosmic body crashed into the Earth, causing
large fires all over the globe. The sudden change of climate wiped out most
of the planet's vegetation and species, including the dinosaurs. Scientists
have long argued whether the Earth was hit by a comet or an asteroid. Until
recently, chemical evidence indicated it was a comet. Now, however, a team
consisting of two Czech and one US scientist has come up with new facts.