NASA Is About to Crash Into an Asteroid. Here’s How to Watch.
An asteroid, going about its own business not too far from Earth, is knocked over by a visitor from our planet.
On Monday, NASA’s Double Asteroid Redirection Test (DART) probe is scheduled to collide with Dimorphos, a small asteroid that is the moon of a larger space rock, Didymos. While these two near-Earth objects pose no immediate threat to our world, NASA launched DART last year to test a technique that could one day be used for planetary defense. Here’s what you need to know about the mission.
When is the collision and how can I watch it?
DART is scheduled to impact Dimorphos at 14,000 miles per hour at 7:14 p.m. Eastern Time Monday.
NASA Television will report on the end of this mission starting at 6:00 p.m. Or you can watch it in the video player embedded above.
If you just want to see a stream of photos from the spacecraft as it approaches the asteroid, NASA’s media channel will begin broadcasting them at 5:30 p.m
Why is NASA crashing into an asteroid?
NASA doesn’t squander an expensive, sophisticated spacecraft just for fun. The agency does its job.
In 2005, Congress gave NASA a mandate to find 90 percent of near-Earth asteroids large enough to destroy a city by 2020 — those 460 feet or more in diameter. But Congress never gave NASA much money to carry out this task, so it remains more than half uncompleted, with about 15,000 more such asteroids to discover.
As the agency scans the skies for deadly space rocks, it also develops methods to respond to a threat should one arise.
The DART mission is not like the movie Armageddon. Blowing up an asteroid would generally not be a good thing. Rather, the mission is proof of the principle that hitting an oncoming asteroid with a projectile can send it into a different orbit.
For a dangerous oncoming asteroid, that nudge could be enough to change trajectory from a direct hit to a near miss.
What happens during the collision?
The mission’s target is Dimorphos, a small asteroid about 500 feet in diameter orbiting a larger object, an 800-meter-wide asteroid called Didymos. A distance of about 0.6 miles separates the two, with Dimorphos completing one orbit around Didymos every 11 hours and 55 minutes.
DART will essentially be a self-propelled suicidal spacecraft navigating its way to its sinking with people at the Johns Hopkins Applied Physics Laboratory Mission Operations Center in Maryland, mostly just bystanders.
“They move extremely fast,” said Elena Adams, the DART mission systems engineer. “And at that point you can’t really send any more orders. So your system has to be very, very precise in how it steers the spacecraft.”
DART’s camera only recognizes Dimorphos as a separate point from Didymos about an hour before the crash. Then it adjusts its trajectory and ends in a glorious collision.
“It’s really hard to hit a very small object in space, and we’re going to make it,” said Dr. adams
What happens if the mission is successful?
If DART and Dimorphos combine as planned, the small asteroid’s orbit will approach that of the larger Didymos. The extent of the change depends on the structure and composition of Dimorphos.
If Dimorphos is solid and DART only carves a small crater, the change follows the basics of a Physics 101 problem – two objects colliding and sticking together. As DART moves in the opposite direction to Dimorphos, it will weaken some of the asteroid’s angular momentum, causing it to approach Didymos and gain speed.
But if Dimorphos is more like a pile of debris held together by gravity, then the impact will create a deep crater and send a shower of debris into space. This cascade of rocks will be like the thrust of a rocket engine pushing against the asteroid. In this case, the orbit of Dimorphos will descend even closer to Didymos.