Huge rocks from space, or asteroids, fall from the sky more than in the past. But you do not have to worry.
A new study shows that over the last 290 million years, the major asteroids collapsed on Earth more than twice as often as they did in the 700 million years before. The journal published the study in January.
But even with the increased crash speed, asteroids still hit the Earth every million or a few million years. observing large cosmic rocks that could collapse in the Earth.
The biggest known risk is a 1.3-kilometer wide asteroid with a 99.988% probability that it will miss the Earth when it passes through 861
A scientist at the University of Toronto Sarah Mazuruy leads a study. She told the Associated Press that she did not worry about the asteroids that hit the Earth because such rare events are.
"It's just a game of probabilities ," she said. and the US on the study. Together they gathered a list of the great scars that asteroids leave on planets and other objects, also known as impact craters.
Researchers looked at the Earth's craters and its moon, which were more than 20 kilometers long. It takes a 800-meter space rock to create such a hole.
They also calculated the dates of the craters. The team has 29 craters that were under 290 million years old. And they found nine of 291 million years ago and 650 million years ago.
Rebecca Gent, another scientist at the University of Toronto, is also working on the study. She noted that we can see relatively few large craters on the surface of the Earth because the planet is more than 70% of the ocean. Also, the movement of large glacial mountains, also known as glaciers, covers some of them
The team estimates that Earth has 260 catastrophes over the last 290 million years. And the crash rate was 2.6 times more than 700 million years ago. As the glaciers mostly covered the older craters, scientists explored moon craters to estimate the age of those between 650 million and 1 billion years on Earth. The moon is close enough to Earth to be on the same path to asteroids and craters last longer.
So, what happened about 300 million years ago? Belt "Masuera suggested. The cosmic rocks then moved toward the Earth and the Moon, Ghent added. Then the planet received several more hits because it was a larger target and there was more gravity.
Other scientists are divided on the team's research. Earth Scientist Jay Melos of Purdue University said he had found that the number of craters was too small to prove a basic point. Avi Low of Harvard University agreed with the team's findings.
Contemporary humans may not have existed without large extinctions from the cosmic rocks, Leeb writes in an email. Most scientists believe that dinosaurs and many other animals have disappeared after a huge cosmic rock crashed in Central America about 65 million years ago.
"This shows how randomly and human
I'm Pitt Musto.
Seth Bornstein reports this story about the Associated Press. Pete Musto adapted it for VOA. Hai Do was an editor. We want to hear from you. How much are you concerned about the asteroid? Write us in the comments section or on our Facebook page.