NASA Trial Mission Targets An Asteroid, Hoping To Learn How To Alter Its Course


Late Tuesday evening PST (Nov. 23), an unmanned NASA spacecraft is scheduled to launch from California on a 6-million-mile suicide mission to slam into an asteroid named Dimorphos. Unlike in a science fiction movie, Dimorphos is not on course to threaten Earth in any way. But the mission, dubbed the Double Asteroid Redirection Test (DART), is designed to explore strategies that could be used someday to alter the course of asteroids that might, indeed, be on a collision course with us.

“It’s a really clever idea,” said Jonathan McDowell, a staff astrophysicist at the Harvard-Smithsonian Center for Astrophysics. “In 2015, Project Deep Impact slammed a spacecraft into a comet and made a large crater.” But there was no way for astronomers to measure whether it had any effect on the comet’s trajectory.

Dimorphos is a different story, and the ideal target for the DART spacecraft, McDowell told AVweb. Measuring about 525 feet across, Dimorphos orbits around a larger, 2,500-foot-wide asteroid named Didymos, which, in turn, orbits around the sun like Earth does. Still, DART hitting even the smaller asteroid is described as like a golf cart hitting a pyramid, but hitting it at 15,000 miles per hour.

“Astrophysicists look for sensitive ways to measure things,” McDowell said. And astronomers can use imaging to determine if Dimorphos’ orbit around Didymos changes as a result of the impact, and by how much.

As challenging as it may sound for NASA, “Hitting the asteroid is the easy part,” McDowell said. More difficult is assessing the density of the asteroid, and how much that will affect future missions to redirect other asteroids that could be a threat to Earth (even a small asteroid the size of Dimorphos could destroy an entire city). The more solid the asteroid, the more energy from the DART will contribute to changing its course. But a “squishy” (McDowell’s word) asteroid could absorb energy from the collision like a giant sponge, minimizing trajectory change. The spacecraft will send back video to NASA of its final moments before impact, hopefully giving astronomers like McDowell and others a good sense of just how “squishy” Dimorphos is.

All this will play out late next year when DART completes its 6-million-mile journey. And just before reaching Dimorphos, the spacecraft will release a photo pod that will observe from above what NASA hopes will be one hell of a crash.

Mark Phelps
Mark Phelps is a senior editor at AVweb. He is an instrument rated private pilot and former owner of a Grumman American AA1B and a V-tail Bonanza.

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      • I would… I just wouldn’t want anyone else to know.
        But, then again, you should live each day like it was your last.
        I think I will go get the multiengine sea plane rating… just because it sounds like fun.

  1. This will probably set up a cosmic pool table effect leading to Earth being destroyed. Oh well, it was a good run.

  2. Better to know your Maker before you meet Him.

    Asteroid or global warming or whatever disaster people think they can/should prevent it matters not at all.

    Ultimately your earthy vessel is mere worm food. It’s just a matter of when and how. The important thing is to focus on your relationships with God and man and plan for your true destiny.

    • The earth has warmed and cooled many times before… it is called following the science. Yes, we have in disputable evidence.
      So… what was better; warm or cool?
      Ask that to someone in Antarctica 🥶and someone in the Sahara desert🥵

  3. Definitely necessary data to have in our tool kit, but only a baby step toward having a practical, flexible “interceptor” package that can deliver sufficient force at a sufficient distance out and on exactly the correct vector. Even with such a package “on the shelf”, the most important thing will always be to have the necessary early warning, something that currently we likely won’t get in the case of smaller objects.