When NASA decided to crash its DART—which stands for Double Asteroid Redirection Test—spacecraft into the Dimorphos asteroid two years ago, it had one clear mission: find out whether it could change the direction of an asteroid on a collision course towards Earth.
In the end, DART was a success, and the world slept better knowing that there was something we could if an asteroid threatened to make us go the way of the dinosaurs. But it looks like NASA’s big discovery may have had some unintentional consequences, according to new research. Specifically, the test may have created the world’s first human-made meteor shower.
The DART mission. As explained by NASA, DART was humankind’s first planetary defense experiment. It aimed to determine whether intentionally crashing a spacecraft into an asteroid, a technique known as kinetic impact, could change its course. Currently, no asteroid larger than 460 feet (140 meters) is expected to hit Earth in the next 100 years, although the possibility isn’t set in stone.
To test out its technology, NASA selected the asteroid Dimorphos, a body with a diameter of 492 feet (150 meters) roughly 7 million miles (11 million kilometers) from Earth. Dimorphos was not on a path to collide with Earth and posed no threat to the planet.
At the time of its impact with Dimorphos, NASA estimated that DART had a mass of 1,280 pounds (580 kilograms). Meanwhile, Dimorphos was assumed to have a mass of roughly 5 billion kilograms.
Crashing a spacecraft into a meteor. In September 2022, NASA crashed DART into Dimorphos. The spacecraft was traveling at a speed of about 14,000 miles (22,530 kilometers) per hour when it made impact. The crash was made official by the sudden appearance of a red screen on NASA's video feed, which indicated the signal had been lost.
Images taken by the Hubble Telescope (left) and the James Webb Telescope (right) taken hours after DART crashed into Dimorphos in 2022.
Data following the impact demonstrated that DART managed to impact Dimorphos’ orbit around Didymos, its parent asteroid, by 32 minutes. The experiment exceeded the benchmark for success, which was 73 seconds or more, more than 25 times.
The first human-made meteor shower. Crashing DART into Dimorphos did more than alter its orbit, though. The impact also created what’s known as ejecta, or pieces of asteroidal rock displaced and launched into space. Months after the mission in 2023, the Hubble Telescope identified dozens of large boulders drifting away from the asteroid. Some scientists believe the boulders could eventually hit Mars.
But a pre-print published this month, which has been accepted for publication by The Planetary Science Journal, highlights other, smaller pieces of debris. In particular, the researchers analyzed three million particles between 30 micrometers and 4 inches (30 centimeters) in diameter. The fragments from Dimorphos were spotted by LICIACube, a spacecraft from the European Space Agency that’s investigating the aftermath of the collision.
An image of the plumes of ejecta, or asteroidal debris, taken by LICIACube after the DART crash.
Based on simulations of their velocities and trajectory, the researchers anticipate that some of the smaller fragments, which are traveling at a speed of 3,350 miles (5,400 kilometers) per hour, could reach Earth within the next decade. However, as noted by Live Science, these fragments are so small that they’re unlikely to result in a meteor shower.
Meanwhile, the larger fragments, which are moving four times slower, could take 30 years to reach us. Researchers believe that these have a higher likelihood of being spotted in the sky as they burn up. If they eventually do arrive, they could create a new meteor shower, which some are calling the “Dimorphids.”
Waiting for the Dimorphids. Eloy Peña-Asensio, the post-doctoral researcher at the Politecnico di Milano who led the study, told Universe Today that meteor observation campaigns in the coming years will determine whether the Dimorphids become reality.
Thanks to their study, which establishes the direction, velocity, and the time of year to observe any possible Dimorphids, they know where to look. There’s no doubt that Peña-Asensio, who points out that the group’s potential meteor shower isn’t dangerous to Earth, will be on the lookout.
“If these ejected Dimorphos fragments reach Earth, they will not pose any risk. Their small size and high speed will cause them to disintegrate in the atmosphere, creating a beautiful luminous streak in the sky,” Peña-Asensio said.
Images | NASA
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