As expected, the DART probe did crash into the asteroid Dimorphos on September 27 at 1:14 a.m. (Paris time). But if the work of the impactor is finished, that of observatories around the world and of astrophysicists can begin! Their mission will culminate in 2024 with ESA’s Hera probe.
And in the meantime, what a collision!
This growing point
It took about an hour before the impact for a tiny point to appear on the images, almost attached to the asteroid Didymos. His little moon Dimorphos, which we could see growing thanks to the DRACO camera of the DART impactor as the latter plunged above him, was revealed little by little. Then, in the last seconds, we could see the surface of the asteroid in all its complexity: large blocks and smaller agglomerates in a “potatoid”. At least, before DART shattered its surface.
The impactor mission is over, and it’s a real success, because NASA has proven that it can aim, then send an autonomous vehicle to crash into a very small body of only 160 m in diameter, 11 million kilometers from Earth. However, there remains the entire second phase of the work, namely observing the effects of this impact and better understanding these asteroid pairs which are relatively frequent and for the moment poorly documented.
It’s good, have you seen it?
The impact itself is properly documented from Earth. This morning, several observatories have already published their images of the collision, showing a very impressive cloud of debris ejected from Dimorphos (which suggests that its density was relatively low and that the effects of the arrival of DART could have upset part of the surface).
On the other hand, the tiny LICIACube satellite did indeed record, about fifty kilometers from the asteroids, a sequence of images of the collision. Its speed of transferring images to Earth is very low, but the first miniatures have been transferred, and everything is very promising. However, studies over several days and several weeks will be needed to quantify exactly the trajectory variations induced by the impact of DART.
Make way for science!
While waiting for 2024 and the departure of the European probe HERA, whose goal will be precisely to study the Didymos/Dimorphos duo as well as the impact of DART on a small body, astrophysicists can console themselves with the film of the approach of the NASA probe. Indeed, the latter already calls into question certain knowledge. For example, it was previously accepted that the parent asteroid Didymos had roughly the same shape as the asteroids Bennu and Ryugu, spheres crushed at their equator. Except that’s not really what the images of the approach show, with an oblong surface, very cratered and which presents many marks…
No doubt, there will be future publications on the subject that will go much further than the images of the DART approach. It is nonetheless a landmark sequence for space exploration which made it possible to receive almost live photographs every 2-3 seconds of a self-guided probe crashing into an asteroid!
Source : The Verge
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