NASA crashed a spacecraft into an asteroid in 2022, and the follow-up science is still finding surprises.
Misryoum newsroom reported that NASA’s DART (Double Asteroid Redirection Test) spacecraft intentionally crashed into a small asteroid called Dimorphos in September 2022. The point was simple—at least on paper: “prove that if a killer space rock ever threatened Earth in the future, humans could deflect it,” according to Misryoum newsroom reporting. The impact was directed at the binary asteroid system, where Dimorphos orbits a larger neighbor, Didymos.
The hit worked, and not just in the way anyone first expected. Misryoum editorial desk noted that the crash changed Dimorphos’s orbit around Didymos to be 33 minutes faster than it was before the strike. But the new findings go beyond that headline result: scientific observations suggest the mission had more far-reaching effects than previously thought, affecting both the struck asteroid and the larger one it orbits. And from the beginning, there was this faint sense of “okay, we’ll see what happens,” like standing near a machine before it fires off—only here it’s space, and you can’t really hear anything except your own thoughts.
Misryoum newsroom reported in a study published in the journal Science Advances that observations “revealed that the 770-day orbital period around the sun changed by a fraction of a second after the DART spacecraft’s impact on Dimorphos,” according to a NASA release. That change, Misryoum editorial team stated, “marks the first time a human-made object has measurably altered the path of a celestial body around the Sun.” Actually, it’s still a tiny alteration—about 150 milliseconds per circle around the sun—so it’s easy to shrug it off.
But scientists are arguing the shrug shouldn’t last. Misryoum analysis indicates that, “given enough time, even a tiny change can grow to a significant deflection.” Thomas Statler, the lead scientist for solar system small bodies at NASA, said in the release that the study “validates kinetic impact as a technique for defending Earth against asteroid hazards and shows how a binary asteroid might be deflected by impacting just one member of the pair.” There’s a logic to that: if one partner in the binary system gets nudged, the dance changes for both.
The mechanics of that nudge may matter as much as the headline numbers. The NASA statement said that when DART hit Dimorphos, the “impact blasted a huge cloud of rocky debris into space, altering the shape of the asteroid.” That debris “carried its own momentum away from the asteroid,” giving it an “explosive thrust.” Misryoum editorial desk noted that the study found the “debris loss doubled the punch created by the spacecraft alone.” And because Dimorphos is part of a binary pair, Misryoum editorial team stated that a “measurable change for one will affect the other.”
Misryoum newsroom reported that Didymos “was never on a path toward Earth, and the DART experiment could not have placed it on one,” according to a press release about the study. Still, the “small shift in orbital speed demonstrates how spacecraft could be used to redirect a threatening asteroid if scientists detect it early enough.” In that scenario, Misryoum analysis indicates a spacecraft would strike the object and “slightly alter its velocity,” and that “tiny change could accumulate into a large enough deviation to prevent a collision with Earth.”
NASA is also working on the Near-Earth Object Surveyor mission, which “could spot dark, risky asteroids that have remained nearly invisible from Earth-based observatories,” said CNN—though, again, the key point here is the pairing: finding a threat, then having a way to change the outcome. Knowing how to identify potential dangers and how to alter their orbit “goes hand in hand with how space agencies envision protecting Earth.” And really, the DART result is a reminder that “hand in hand” can start with something as blunt as a crash, then expand into a whole new understanding of what the system does afterward—if you watch it closely enough.