It's worse than thought: the collision of the NASA vehicle with an asteroid scattered its debris for thousands of kilometers. Photo
As a result of the collision of the spacecraft DART (Double Asteroid Redirection Test - translated as Double Asteroid Redirection Test) with the asteroid satellite Dimorphos from the surface of the latter was thrown 37 large boulders scattered to thousands of kilometers.
The debris was discovered by a group of researchers who studied the data from the Hubble telescope. The scientists reported their discovery in an article for The Astrophysical Journal Letters.
The collision of the DART apparatus and 160-meter Dimorphos occurred on September 26, 2022 and was declared successful, because thanks to this asteroidal satellite was able to shift from its initial trajectory. Thus, NASA tested the theory of whether it is possible to throw an asteroid off course if it, for example, threatens the Earth.
Later, however, it turned out that the impact was much stronger, and Dimorphos accelerated its rotation around Didymos not by 7 minutes, as NASA had planned, but by 33 minutes. Read more about it here.
Now, thanks to the Hubble telescope, it has been discovered that the collision with Dimorphos ejected 37 boulders ranging in size from 1 meter to almost 7 meters! They were scattered over an area of about 10,000 kilometers.
At first, the astronauts thought they were debris that had been knocked off the asteroid as a result of the collision, but it turned out to be rocks that had been lying on the surface of Dimorphos.
The team of astronomers in the article notes that by cosmic standards boulders are very small, so they could only see them thanks to the high sensitivity of Hubble.
Images of the boulders surrounding Dimorphos were taken on December 19, 2022.
A few moments before the collision, the DRACO DART camera sent an image of Dimorphos, which shows a surface covered with boulders of various shapes and sizes. Astronomers are not yet sure exactly how the boulders were "lifted" from the asteroid's surface.
It is speculated that they could have been part of the large ejection plume observed by Hubble and other observatories after the collision. Alternatively, scientists speculate that the seismic wave from the impact may have shaken the asteroid and ejected the debris.
"The number, size, and shapes of boulders photographed with Hubble are consistent with them being objects dislodged from about 2% of (Dimorphos') surface due to the DART impact," the team wrote in their paper.
The scientists also said that the boulders are moving away from the asteroid at a relatively slow speed of 0.8 kilometers per hour.
"This is an impressive observation - much better than I expected. We see a cloud of boulders carrying mass and energy from entire collisions. The number, size and shapes of the boulders are consistent with them being knocked off the surface of Dimorphos by the collision," said David Jewett, a planetologist at the University of California, Los Angeles.
DART weighed 610 kilograms and crashed into Dimorphos at about 22,530 km/h. The collision reduced the asteroid's orbital velocity and decreased its orbital radius.
DART dug a crater on the surface of Dimorphos, ejecting more than 990 tons of debris into space. The collision also changed the trajectory of the parent asteroid, Didymos. Thanks to the new data, astronomers are almost certain that Dimorphos is a debris asteroid. These are asteroids made up of assembled fragments of broken monolithic asteroids and are much more common in the solar system than previously thought.
Earlier OBOZREVATEL told about the fact that asteroid collisions with the Earth can be much more catastrophic than scientists believed.