Nov 23, 2021 - Science

NASA's 911 for asteroids

Illustration: Trent Joaquin/Axios

SpaceX is set to launch a NASA spacecraft on a mission to learn how to change the course of an asteroid in deep space.

Why it matters: The mission — called the Double Asteroid Redirection Test (DART) — will test the technology needed to redirect a dangerous asteroid if one is ever found on course with Earth.

Driving the news: The SpaceX Falcon 9 is expected to launch DART to space at 1:21 a.m. ET Wednesday.

  • NASA will air live coverage of the launch starting at 12:30 a.m. ET Tuesday, for all you night owls.

How it works: Once in space, DART will make its way to a tiny asteroid called a "moonlet" named Dimorphos that orbits the larger asteroid Didymos.

  • DART, which will weigh about 1,345 pounds at launch, will slam into Dimorphos in the fall of 2022 to see if it can shift the course of the moonlet.
  • The asteroid system isn't in danger of impacting Earth, making it a good target for this type of experiment. It's also positioned well for scientists on Earth to monitor the two asteroids in the system with observatories on the ground.
  • "The right time to deflect an asteroid is as far away from the Earth as we can," Lindley Johnson, planetary defense officer for NASA, said during a news conference. "The farther away in space it is... the less force it takes to change the orbit enough that it will be a miss instead of a hit."

The big picture: NASA and other space agencies track potentially dangerous asteroids as they make their way around the Sun.

  • NASA says its found 90% of all the near-Earth objects 3,280 feet long or larger, and the agency is now working on finding 90% of those types of objects that are 459 feet long or larger.
  • As of June 2021, the agency had found about 40% of the asteroids in that smaller size range.

What to watch: Eventually, new telescopes on the ground and in space, like the Near-Earth Object Surveyor space telescope currently in development at NASA, will allow scientists to find and track asteroids that are difficult to see today.

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