Hera In The Media
On 26 September 2022, NASA’s Double Asteroid Redirection Test (DART) mission successfully impacted Dimorphos, the natural satellite of the binary near-Earth asteroid (65803) Didymos. Numerical simulations of the impact provide a means to find the surface material properties and structures of the target that are consistent with the observed momentum deflection efficiency, ejecta cone geometry and ejected mass. Our simulation that best matches the observations indicates that Dimorphos is weak, with a cohesive strength of less than a few pascals, like asteroids (162173) Ryugu and (101955) Bennu. We find that the bulk density of Dimorphos is lower than ~2,400 kg m−3 and that it has a low volume fraction of boulders (≲40 vol%) on the surface and in the shallow subsurface, which are consistent with data measured by the DART experiment. These findings suggest that Dimorphos is a rubble pile that might have formed through rotational mass shedding and reaccumulation from Didymos. Our simulations indicate that the DART impact caused global deformation and resurfacing of Dimorphos. ESA’s upcoming Hera mission may find a reshaped asteroid rather than a well-defined crater.
https://www.nature.com/articles/s41550-024-02200-3
The NASA DART first results have just did the cover of the journal Nature. Hera mission team members were among the scientists doing the cover of the international scientific journal Nature about the NASA’s Double Asteroid Redirection Test (a.k.a. DART) space mission’s scientific results. Three of the five open-access papers published in the journal Nature presenting the first results of the NASA DART mission acknowledge support from the European Space Agency. These papers made the cover of the journal on its 20 April 2023 issue.
Extract: “Although currently there is no known threat to Earth from asteroids, strategies to protect the planet from a collision are being explored. On 26 September 2022, NASA and the Johns Hopkins Applied Physics Laboratory successfully tested one such approach: the Double Asteroid Redirection Test (DART) spacecraft was deliberately crashed into Dimorphos, a moon orbiting the small asteroid Didymos, resulting in a change in the moon’s orbit. In this week’s issue, five papers explore the test and the effects of the collision. One paper reconstructs the impact; a second looks at the change to Dimorphos’s orbit caused by the impact. A third paper reports observations from the Hubble Space Telescope of the material ejected during the collision. A fourth paper uses modelling to characterize the transfer of momentum that resulted from the impact. And the final paper reports on citizen science observations before, during and after the collision.”
https://www.nature.com/articles/s41586-023-05810-5
https://www.nature.com/articles/s41586-023-05811-4
https://www.nature.com/articles/s41586-023-05878-z
Le 17 octobre 2022 s’est tenu, à l’Hôtel de Ville de Nice (France), une conférence au cours de laquelle le Dr. Patrick MICHEL, coordinateur du Projet NEO-MAPP, a reçu, des mains de monsieur le maire Christian ESTROSI, l’Aigla Nissarda d’argent, en récompense de sa contribution au rayonnement de la ville.
Le Dr. Patrick MICHEL est Directeur de recherche CNRS du laboratoire Lagrange à l’Observatoire de la Côte d’Azur (Université de la Côte d’Azur) et Coresponsable de la collaboration spatiale internationale AIDA (pour Asteroid Impact Deflection Assessment). AIDA comprend deux missions de défense planétaire autonomes : la mission DART de la NASA et la mission Hera de l’ESA. Patrick MICHEL est à la fois Membre de DART et Responsable scientifique de Hera. Il nous fait un retour d’expérience sur la grande réussite des opérations relatives à l’impacteur DART, qui a volontairement ciblé et atteint le satellite naturel Dimorphos de l’astéroïde Didymos. Enfin, il nous parle de la suite, la sonde Hera, qui sera lancée en 2024 depuis Cap Canaveral par une Falcon 9 de Space X et arrivera à son rendez-vous avec l’astéroïde double Didymos – Dimorphos en 2027, pour une visite, et à proprement parler une enquête complète, d’une durée totale de 6 mois.
Crédit vidéo : Ville de Nice (Alpes-Maritimes, France)
Crédit photo : Julien SERRECOURT (CNRS, NEO-MAPP)
Hera is a planetary defense mission under development in the Space Safety and Security Program of the European Space Agency for launch in 2024 October. It will rendezvous in late 2026 December with the binary asteroid (65803) Didymos and in particular its moon, Dimorphos, which will be impacted by NASA’s DART spacecraft on 2022 September 26 as the first asteroid deflection test. The main goals of Hera are the detailed characterization of the physical properties of Didymos and Dimorphos and of the crater made by the DART mission, as well as measurement of the momentum transfer efficiency resulting from DART’s impact.
Abstract from: The Planetary Science Journal (open access), 3:160 (21pp), 2022 July.
Small-scale impacts may significantly deform weak asteroids. A team of researchers led by Sabina Raducan and Martin Jutzi from the University of Bern and the National Centre of Competence in Research PlanetS recently developed a novel approach, which, for the first time, enabled them to model the entire cratering process resulting from impacts on small, weak asteroids.
On June 1st, 2022, during the Hera international workshop in Nice (France), Dr. Sabina Raducan (Univ. Bern, Swirzerland) and Dr. Yun Zhang (Univ. Maryland, USA, Lagrange Lab/CNRS/OCA, France) were awarded the first Hera Certificate in recognition to their outstanding contribution to the Hera mission.
Fin novembre 2022, la mission DART de la NASA enverra une sonde spatiale sur un astéroïde qui sera situé à onze millions de kilomètres de la Terre au moment de l’impact. Objectif : tenter de dévier sa trajectoire.
Réunis en colloque à Nice du 30 mai au 3 juin, sous l’égide de l’Observatoire de la Côte d’Azur (Université Côte d’Azur), les scientifiques de la mission Hera (ESA) travaillent sur la sonde qui enquêtera à la suite du premier test de déviation d’un astéroïde par la mission DART (NASA).
Comment se préparer de manière anticipée à toutes éventualités et créer des solutions pour les générations futures, en cas de menace provenant d’un astéroïde géocroiseur.
Entretien avec Patrick MICHEL devant le Golden Gate Bridge
Avec Patrick Michel, P.I. de Hera, Observatoire de la Côte d’Azur, Laboratoire Lagrange, CNRS
Émission Camille Passe Au Vert, avec Patrick Michel, P.I. de Hera, Observatoire de la Côte d’Azur, Laboratoire Lagrange, CNRS
Les chercheuses Mélanie Drilleau et Naomi Murdoch, de l’ISAE-SUPAERO, participent à la première mission internationale de défense planétaire
Émission C'Est Arrivé Cette Semaine, avec Patrick Michel, P.I. de Hera
Émission L'Invité Du 6h20, avec Patrick Michel, P.I. de Hera
Journal Le 12/13, avec Ian Carnelli (ESA-ESTEC) et Manager de la mission Hera à l’ESA
Conférence Société Astronomique de Cannes (SACA) par Patrick Michel
Horizon: the EU Research & Innovation magazine
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