Remember when NASA deliberately crashed a spacecraft into an asteroid last year? Well, the aftermath of that cosmic collision just got a whole lot more interesting.
In a groundbreaking study published in the Planetary Science Journal, scientists have uncovered some unexpected results from NASA’s Double Asteroid Redirection Test (DART) mission. It turns out that when DART slammed into the asteroid moon Dimorphos in 2022, it didn’t just leave a dent – it completely reshaped the celestial body and potentially set it on a chaotic new path.
Breaking down what happened and why it matters
First, a quick refresher: DART was NASA’s test run for planetary defense. The idea was to see if we could change the course of an asteroid by hitting it with a spacecraft – kind of like a game of cosmic billiards. The target was Dimorphos, a small asteroid moon orbiting a larger asteroid called Didymos.
Now, here’s where things get interesting. According to Derek Richardson, a professor of astronomy at the University of Maryland and a lead researcher on the DART mission, the impact did more than just nudge Dimorphos off course. It dramatically altered its shape.
Richardson explains that one of the biggest surprises was how much the shape of Dimorphos changed as a result of the DART mission. Originally, the asteroid moon was shaped like a hamburger, but the collision stretched it into the shape of a football.
This shape change is a big deal because it challenges what scientists thought they knew about how asteroid moons form. Previously, they believed these moons would naturally become elongated over time, always pointing their long axis toward the main asteroid they orbit. However, Dimorphos flipped the script, going from squished to stretched after the impact.
“This result contradicts that idea and indicates that something more complex is at work here. Furthermore, the impact-induced change in Dimorphos’ shape likely changed how it interacts with Didymos,” Prof. Richardson says in a university release.
The surprises didn’t stop with the asteroid moon changing shape. The DART impact may have set Dimorphos tumbling through space in an unpredictable way. Before the collision, Dimorphos was likely in a stable state, always showing the same face to Didymos (much like our Moon always shows the same face to Earth). Now? Not so much.
“Now, it’s knocked out of alignment, which means it may wobble back and forth in its orientation,” Richardson explains. “Dimorphos might also be ‘tumbling,’ meaning that we may have caused it to rotate chaotically and unpredictably.”
This unexpected tumbling raises new questions about the asteroid’s stability and internal structure. It could take a century or more for Dimorphos to settle back into a stable state, which has implications for future asteroid research and potential planetary defense strategies.
Speaking of future research, the European Space Agency is planning a follow-up mission called Hera, set to launch in October 2024. Hera will arrive at the Didymos-Dimorphos system in late 2026 to study both asteroids up close and provide more details about DART’s impact. One key question Hera might help answer is whether Dimorphos is stable enough for future spacecraft to land on.
“One of our biggest questions now is if Dimorphos is stable enough for spacecraft to land and install more research equipment on it,” Richardson notes.
While all of this might sound like abstract space science, it has very real implications for our planet’s safety. The DART mission and its aftermath are helping scientists refine strategies for defending Earth against potential asteroid or comet impacts.
“DART gave us insight into complicated gravitational physics that you can’t do in a lab, and all of this research helps us calibrate our efforts to defend Earth in the event of an actual threat. There’s a nonzero chance that an asteroid or comet will approach and endanger the planet. Now, we have an additional line of defense against these kinds of external threats,” Richardson concludes.
Source: https://studyfinds.org/nasa-asteroid-moon-dart/?nab=0