Thus astronomers can put a new check mark on the space mission’s to-do list. The researchers previously established that Dimorphos shifted its orbit slightly due to the impact of the Dart space probe, the “bullet” in question. This orbital change was the main goal of the mission, which serves as a test to see if humanity ever wants to deflect a space rock on a collision course with Earth.
“The composition of such an asteroid, how it reacts to a collision, the question of whether large fragments come out of it — you all want to know that if you want to change the orbit of such an asteroid precisely,” says astronomer Lukas Ellerbrock, who himself is not involved in the research. The analysis, carried out with the Very Large Telescope atop a mountain in Chile, showed, among other things, that the debris cloud is composed primarily of small grains shortly after the collision. Then, larger fragments were fired, presumably from the deeper interior of the space rock. The researchers published their findings in two separate professional articles Tuesday afternoon.
every penny
In the past, Ellerbroek has analyzed results from the European Rosetta mission, in which the probe took samples from a comet and analyzed them while floating in space. A similar geological survey was carried out this time, but this time from the ground – though that was mainly bycatch. “Usually you wouldn’t do this by crashing a multimillion-euro probe into an asteroid, but now it’s smart enough to take a look. This is how every penny invested turns into interesting science. The analysis basically confirmed things that scientists had already suspected, Like these types of asteroids actually don’t contain water.
“These kinds of analyzes provide science with a whole library of knowledge, which teaches us, among other things, how we can play balls with these types of asteroids,” says Ellerbroek. This knowledge is being used, for example, to calibrate computer models that predict when and how they should hit a rock if it is in fact on a collision course with the ground.
In the short term, this is only possible for smaller space rocks a few hundred meters in diameter. With a bit of bad luck, they can destroy a city. For larger specimens, like the asteroid that killed the dinosaurs, the technology just doesn’t work at the moment. Fortunately, such impacts are rare: on average only once every hundred million years, astronomers estimate.
The next check mark on the Dart mission list will be at the end of 2026. Then the European space probe Hera, which will leave Earth next year, will arrive at Dimorphos. There, Hera will study the impact crater in more detail.
