Earth is bombarded at random | ETH Zurich
https://www.ethz.ch/en/news-and-events/eth-news/news/2017/03/earth-is-bombarded-at-random.html
Asteroids don’t hit our planet at regular intervals, as was previously thought. Earth scientists from ETH Zurich and Lund University in Sweden
have reached this conclusion after analysing impact craters formed in the last 500 million years, concentrating on precisely dated events.
Do mass extinctions, like the fall of the dinosaurs, and the formation of large impact craters on Earth occur together at regular intervals?
“This question has been under discussion for more than thirty years now,” says Matthias Meier from ETH Zurich’s Institute of Geochemistry and
Petrology. As late as 2015, US researchers indicated that impact craters were formed on Earth around every 26 million years. “We have determined,
however, that asteroids don’t hit the Earth at periodic intervals,” says Meier, refuting the popular hypothesis.
In the past, researchers have even postulated the existence of a companion star to the Sun. This supposed dim dwarf star, named Nemesis after
the Greek goddess of revenge, was believed to draw near to the Sun every 26 million years and cause asteroids to bombard Earth. This would
next occur in around 10 million years. Nemesis, however, has never been found.