The good news? No giant asteroids will strike this millennium.
A new study by University of Colorado and NASA scientists and accepted for publication in The Astronomical Journal, extended forecasts for the biggest known near-Earth asteroids by an order of magnitude and found none threaten Earth in the next thousand years.
Don’t Look Up. In 1998, NASA asked scientists to find 90 percent of all near-Earth asteroids bigger than a kilometer.
The 10-kilometer-wide asteroid that killed off the dinosaurs 66 million years ago belonged to this club.
“This is what we call a planet killer,” astronomer Scott Sheppard told the New York Times last year after scientists found a new 1.5-kilometer asteroid.
NASA has since discovered nearly a thousand asteroids over a kilometer wide, or around 95 percent of the total in existence.
This catalog includes observations that help astronomers calculate each asteroid’s orbit and model the likelihood it’ll impact Earth in the future. As asteroids careen around the sun, their orbits are tugged about by the gravity of the planets. Looking ahead a thousand years, the team found the vast majority of asteroids didn’t spend much time in our neighborhood and could be ruled out as hazardous.
Next, they identified the population of large asteroids that most frequently buzz by Earth. The asteroid with the highest probability of impact is 1994 PC1, a kilometer-wide asteroid that passes close to Earth often. The space rock Sheppard was referring to last year is a member of a group of large asteroids hiding in the glare of the sun. The team write they’d like to apply their approach to extend forecasts for smaller asteroids too.
Should we discover a dangerous smaller asteroid in the future, NASA’s DART mission last year showed we might push it off-course and prevent a strike with enough advance warning.