A spacecraft crashing into an asteroid might sound like a terrible mistake. But NASA, the U.S. space agency, plans to make that happen later this year.
The unmanned spacecraft, called DART, blasted off from Vandenberg Space Force Base in California in November. Early next fall, it’s expected to reach its target: an asteroid called Dimorphos. DART will slam into the space rock at 15,000 miles per hour. The goal is to slow the asteroid’s speed and slightly change its path.
Scientists say Dimorphos poses no danger to us. The closest it has come to Earth is about 4.5 million miles. So why send DART into deep space just to be destroyed?
“The purpose of this test is to demonstrate that we can deflect an asteroid that might someday be a hazard to Earth,” says Lindley Johnson, NASA’s planetary defense officer.
Scientists at NASA and other space agencies are tracking more than a million asteroids orbiting the sun. Luckily, most of them fly harmlessly by our planet.
Thousands of small space rocks enter Earth’s atmosphere each year, but most burn up before reaching the ground. Others fall into the ocean.
A huge asteroid hitting Earth isn’t out of the question, however. An asteroid the size of a small city smashed into part of present-day Mexico about 65 million years ago. It may have been what wiped out the dinosaurs.
Scientists say there’s little threat of anything like that happening in the next 100 years. But DART will help them prepare, just in case.