For generations, the debate has raged as to what exactly caused the extinction of the dinosaurs 65 million years ago. Following a series of varying suggestions, the latest research proposes that the widely-held belief that an asteroid collided with the earth to cause a catastrophic chain of events is wrong. Sort of.
Researchers in the USA announced earlier this month that rather than an asteroid, the impact of the Chicxulub crater in Mexico was caused by a comet. The difference between the two interstellar objects is that comets are made of ice, rock and dust whereas asteroids are made predominantly of metals.