ESA observes the outcome of the impact of DART on Dimorphos
Last night at 23:14 UTC NASA's DART spacecraft successfully hit Dimorphos, the moonlet orbiting around near-Earth asteroid Didymos. About 38 seconds later, the time it took for the light to reach Earth, people all over the world saw the abrupt end of the live streaming from the spacecraft, signaling that the impact had happened successfully.
At the same time, astronomers in a small slice of our planet surface, extending from Southern and Eastern Africa to the Indian Ocean and the Arabian Peninsula, could actually watch it live with their telescopes. Among those were a half dozen stations joined together for a dedicated observing campaign organized by our ESA Planetary Defence Office, and coordinated by the team of observers of the NEO Coordination Centre. As usual, when such a timely astronomical event happens, not all stations were successful in their observations: clouds, technical problems and other issues always affect real-life observations.
However, a few of our collaborating stations could immediately report a successful direct confirmation of the impact. Among them was the team of the Les Makes Observatory, on the French island of La Reunion, in the Indian Ocean. The sequence of images they provided in real time was impressive: the asteroid immediately started brightening upon impact, and within a few seconds it was already noticeably brighter. Within less than a minute a cloud of ejected material became visible, and we could follow it while it drifted Eastward and slowly dissipated.
The emotion of following the event live was the conclusion of weeks of discussions, meetings, accurate planning and observational design by our team, together with the local observers and scientists at all the collaborating stations. A fantastic campaign that produced data that our astronomers, together with the whole DART collaboration, will now begin analysing in order to extract valuable scientific information on the effects of the impact. The results will prepare us for the visit of ESA's Hera spacecraft to the Didymos system to examine the aftermath of the DART's impact a few years from now.
Observations of Didymos during the DART impact. A clear brightnening just after the impact can be observed, followed by a cloud of material ejected from Dimorphos. Credits: Les Makes observatory, J. Berthier, F. Vachier / T. Santana-Ros / ESA NEOCC, D. Föhring, E. Petrescu, M. Micheli