NASA Conducts Earth’s First Planetary Defense Test Mission

NASA smashes unmanned spacecraft into asteroid at 14,700 mph

By Jonny Lupsha, Wondrium Staff Writer

On September 26, NASA tested Earth’s asteroid defense capabilities. NASA intentionally crashed a spacecraft into a dual asteroid to determine how the asteroid’s trajectory could be changed. The impact of asteroids hitting the Earth could be devastating.

Small and large asteroids over Earth
Thirty space organizations worldwide participate in the International Asteroid Warning Network to coordinate observation and response efforts of asteroids bound toward Earth. Photo by buradaki / Shutterstock

For anyone interested in the universe beyond Earth, applying for a job at NASA just got a whole lot more appealing. On Monday, September 26, NASA confirmed the success of the Double Asteroid Redirection Test (DART). DART’s mission was to send a small, unmanned spacecraft directly into a 530-foot asteroid, named Dimorphos, to test whether humanity could deflect an asteroid or comet on its way toward Earth. Aside from just being really cool, DART became Earth’s first-ever planetary defense test.

DART flew through space for 10 months before completing its mission of hitting the targeted asteroid, in what is nothing short of a master class in physics and marksmanship. On the subject of how its success will be measured, Dimorphos orbits a much larger asteroid called Didymos. Since the test, NASA scientists have begun studying the change in Dimorphos’s orbit around Didymos to gauge DART’s effectiveness.

Neither asteroid was a threat to Earth, but asteroids, in general, are cause for concern. In the new Wondrium series, in partnership with Scientific American magazine, Mind-Blowing Science: Season 2, the episode on asteroid defense explains the threat that asteroids pose—and how DART is testing our readiness against such a threat.

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“Planetary Defense” is often defined as “the attempt to identify and prevent potential collisions between asteroids or comets and this planet.” Of course, the likelihood of this event is low, but it’s not impossible—and it’s happened before.

An asteroid the size of a six-story building broke up over the town of Chelyabinsk, Russia, in February 2013, injuring 1,600 people. In 1908, an asteroid devastated the remote area of the Podkamennaya Tunguska River in Siberia. And of course, the asteroid associated with the death of the dinosaurs wiped out 70% of life on Earth.

That’s why NASA has an entire office devoted to the problem. In fact, as stated in Mind-Blowing Science: Season 2, 30 space organizations worldwide, including “dedicated amateurs, national space agencies, and individual observatories,” participate in the International Asteroid Warning Network. The network was suggested by the United Nations and forms coordinated observation and response efforts, globally. Since 2016, the network has logged more than 300 close approaches of asteroids toward Earth.

Throwing Darts

The DART mission was launched on November 24, 2021. The episode on asteroid defense in Mind-Blowing Science: Season 2 further explains that changing Dimorphos’s orbit around Didymos should also change Didymos’s orbit around the Sun. The 610-kilogram spacecraft hit the 4.8-billion kilogram asteroid at a speed of 6.58 km per second (over 14,700 miles per hour).

“The general technique would work in single-asteroid systems, too—You can slam a spacecraft into a loner. But scientists have good reason for choosing a double system for this test. It is simple to measure how much you change a moon’s orbit, because you can just watch it pass in front of the larger asteroid in real-time.”

The small, unmanned spacecraft that crashed into Dimorphos cost $250 million, but the insight NASA gained for purposes of planetary defense could be immeasurable, only to be realized in the future.

Mind-Blowing Science: Season 2 is now available to stream on Wondrium.

Edited by Angela Shoemaker, Wondrium Daily