The DART (NASA) and Hera (ESA) missions offer the first fully documented asteroid deflection test based on the kinetic impactor technique, allowing us to check and potentially validate our impact numerical models at the real scale of an asteroids. DART succesfully tackled the challenge to deflect the small moon, called Dimorphos, of the binary asteroid Didymos on September 26th, 2022, causing a decrease of the orbital period of Dimorphos around its primary. But many questions remain that will be answered by the Hera mission. Moreover, images sent by space missions to asteroids reveal that these objects are not simple rocks in space but very complex small geological world, whose response to external actions in their low gravity environment challenges our intuition. What did we learn from past missions, what are the challenges, the surprises and the remaining uncertainties? How will Hera measure the outcome of the DART impact and the properties of the asteroid? This presentation will address these questions that are not only relevant for planetary defense but also for the scientific understanding of those small worlds, which are the remnants of the bricks that formed our planets, and of the impact process, which plays a major role in all phase of our Solar System history.
Patrick Michel is Director of Research at CNRS (French Scientific Research National Center) and leads the Planetology team of the Lagrange laboratory at the Côte d’Azur Observatory (Nice, France). He is also Global Fellow (Professor with a foreign permanent affiliation) of the University of Tokyo (School of Engineering, Japan). With more than 220 publications in international peer-review journals, he develops numerical simulations of the impact process between asteroids, which reproduced for the first time real asteroid families, and of their surface and interior in their low-gravity environment.
Webinar was recorded on June 1, 2023