High school students unveil new data on NASA’s earth-killer asteroid experiment

Art Raymond
Thu, September 14, 2023 

This illustration made available by Johns Hopkins APL and NASA depicts NASA’s DART probe. | Steve Gribben, Johns Hopkins via Associated Press

Was last year’s NASA test to push a potential planet-killing asteroid away from Terra Prime even more successful than previously thought?

A group of California high school students used their school’s observatory to monitor the aftermath of the DART mission’s collision with the distant Dimorphos asteroid last September and discovered the intentional crash worked even better than early NASA data indicated.

Sponsored by NASA’s Planetary Defense Coordination Office and led by the Johns Hopkins University Applied Physics Laboratory, the Double Asteroid Redirection Test, or DART, is a $325 million project designed to crash the 1,260-pound spacecraft traveling at 14,000 mph into Dimorphos, an asteroid that’s 525 feet in diameter and 7 million miles from Earth.

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The point of the exercise was to see how significantly the previous path of Dimorphos could be altered by the impact in a technique NASA calls “asteroid deflector by kinetic impactor.”



Dimorphos is a moonlet asteroid, orbiting a larger asteroid named Didymos, which is about a half-mile in diameter. Mission officials have stressed throughout the DART mission that the binary system “is not on a path to collide with Earth and therefore poses no actual threat to the planet” but is the “perfect testing ground” to see if an asteroid’s natural path can be altered via a high-velocity impact.

Before DART’s impact, it would take Dimorphos 11 hours and 55 minutes to make one revolution around Didymos. NASA was hoping the DART collision could alter the cycle by about 73 seconds, but observations made in the weeks following impact determined the results were much more significant, altering Dimorphos’ revolution period by some 33 minutes.

But students from the Thacher School, a private boarding school for ninth through 12th graders in Ojai, California, used the school’s own research-grade observatory to track Dimorphos and Didymos for several months last fall. Their findings revealed that Dimorphos’ orbital period was a full minute longer than the time reported by NASA last year, according to a recent report in New Scientist.

The Thacher School’s student findings brought the asteroid’s orbital period to 34 minutes shorter than it was pre-impact.

“That was inconsistent at an uncomfortable level,” Jonathan Swift, a math and science teacher at the Thacher School who took part in the research, told New Scientist, per Smithsonian Magazine. “We tried our best to find the crack in what we had done, but we couldn’t find anything.”

The unexpected findings were first shared by Swift and his students at a June meeting of the American Astronomical Society and the methodology was confirmed to Smithsonian Magazine by Peter Veres, an astronomer at the Center for Astrophysics, Harvard & Smithsonian.

Scientists aren’t sure exactly what is behind the degradation of Dimorphos’ orbital time around Didymos but one theory posits that giant boulders and other material that was blasted off the asteroid following the DART collision may be falling back to the surface, resulting in more collisions that are reducing its orbital cycle, according to Smithsonian Magazine’s report.

Right now, no known asteroid larger than 140 meters in size has a significant chance to hit Earth for the next 100 years, but only about 40% of those asteroids have been found as of October 2021, according to NASA.

As the collective knowledge-base and expertise grows to include comprehensive identification and tracking of future potential hazards from space, NASA Program Scientist Tom Statler last year said the DART mission will help prepare the residents of Earth to take effective action in the event of some distant, pending catastrophe.