High-speed Boulders and the Debris Field in DART Ejecta
Abstract On 2022 September 26 the Double Asteroid Redirection Test (DART) spacecraft collided with Dimorphos, the moon of the near-Earth asteroid 65803 Didymos, in a full-scale demonstration of a kinetic impactor concept. The companion Light Italian Cubesat for Imaging of Asteroids (LICIACube) spacecraft documented the aftermath, capturing images of the expansion and evolution of the ejecta from 29 to 243 s after the impact. We present results from our analyses of these observations, including an improved reduction of the data and new absolute calibration, an updated LICIACube trajectory, and a detailed description of the events and phenomena that were recorded throughout the flyby. One notable aspect of the ejecta was the existence of clusters of boulders, up to 3.6 m in radius, that were ejected at speeds of up to 52 m s −1 . Our analysis of the spatial distribution of 104 of these boulders suggests that they are likely the remnants of larger boulders shattered by the DART spacecraft in the first stages of the impact. The amount of momentum contained in these boulders is more than 3 times that of the DART spacecraft, and it is directed primarily to the south, almost perpendicular to the DART trajectory. Recoil of Dimorphos from the ejection of these boulders has the potential to change its orbital plane by up to a degree and to impart a non-principal-axis component to its rotation state. Damping timescales for these phenomena are such that the Hera spacecraft, arriving at the system in 2026, should be able to measure these effects.
Authors
- R. T. Daly (ORCID: https://orcid.org/0000-0002-1320-2985)
- Masatoshi Hirabayashi (ORCID: https://orcid.org/0000-0002-1821-5689)
- Marilena Amoroso (ORCID: https://orcid.org/0000-0003-2603-165X)
- Alice Lucchetti (ORCID: https://orcid.org/0000-0001-7413-3058)
- Ivano Bertini (ORCID: https://orcid.org/0000-0002-0616-2444)
- Jian‐Yang Li (ORCID: https://orcid.org/0000-0003-3841-9977)
- Michèle Lavagna (ORCID: https://orcid.org/0000-0003-4361-1437)
- Sabina D. Raducan (ORCID: https://orcid.org/0000-0002-7478-0148)
- J. R. Brucato (ORCID: https://orcid.org/0000-0002-4738-5521)
- Megan Bruck Syal (ORCID: https://orcid.org/0000-0003-2776-9955)
- O. S. Barnouin (ORCID: https://orcid.org/0000-0002-3578-7750)
- Sean Wiggins (ORCID: https://orcid.org/0000-0003-1698-1037)
- T. J. Stubbs (ORCID: https://orcid.org/0000-0002-5524-645X)
- F. Marzari (ORCID: https://orcid.org/0000-0003-0724-9987)
- Andrea Capannolo (ORCID: https://orcid.org/0000-0002-4917-287X)
- D. A. Glenar (ORCID: https://orcid.org/0000-0003-2155-3854)
- Marco Zannoni (ORCID: https://orcid.org/0000-0002-4151-9656)
- Kathryn M. Kumamoto (ORCID: https://orcid.org/0000-0002-0400-6333)
- M. Dall’Ora (ORCID: https://orcid.org/0000-0001-8209-0449)
- Giovanni Poggiali (ORCID: https://orcid.org/0000-0002-3239-1697)
- Giovanni Zanotti
- Dario Modenini (ORCID: https://orcid.org/0000-0002-1517-3938)
- A. M. Stickle (ORCID: https://orcid.org/0000-0002-7602-9120)
- G. Cremonese (ORCID: https://orcid.org/0000-0001-9021-1140)
- Simone Pirrotta (ORCID: https://orcid.org/0000-0003-0377-8937)
- T. L. Farnham (ORCID: https://orcid.org/0000-0002-4767-9861)
- P. Palumbo (ORCID: https://orcid.org/0000-0003-2323-9228)
- Andrew F. Cheng
- Vincenzo Della Corte (ORCID: https://orcid.org/0000-0001-6461-5803)
- Evan Bjonnes (ORCID: https://orcid.org/0000-0002-6170-8171)
- Angelo Zinzi (ORCID: https://orcid.org/0000-0001-5263-5348)
- J. M. Sunshine (ORCID: https://orcid.org/0000-0002-9413-8785)
- Ramin Lolachi (ORCID: https://orcid.org/0000-0001-5764-7639)
- E. Dotto (ORCID: https://orcid.org/0000-0002-9335-1656)
- A. Rossi (ORCID: https://orcid.org/0000-0001-9311-2869)
- E. Mazzotta Epifani (ORCID: https://orcid.org/0000-0003-1412-0946)
- Stavro Ivanovski (ORCID: https://orcid.org/0000-0002-8068-7695)
- Harrison Agrusa (ORCID: https://orcid.org/0000-0002-3544-298X)
- Gabriele Impresario (ORCID: https://orcid.org/0000-0001-8984-4231)
- M. Pajola (ORCID: https://orcid.org/0000-0002-3144-1277)
- P. H. Hasselmann (ORCID: https://orcid.org/0000-0003-1193-8945)
- J. D. P. Deshapriya (ORCID: https://orcid.org/0000-0002-5758-1286)
- C. M. Ernst (ORCID: https://orcid.org/0000-0002-9434-7886)
- Igor Gai (ORCID: https://orcid.org/0000-0002-5367-3650)
- Paolo Tortora (ORCID: https://orcid.org/0000-0001-9259-7673)
- Simone Ieva (ORCID: https://orcid.org/0000-0001-8694-9038)
- Eugene G. Fahnstock
Institutions
- University of Bern (CH)
- Lawrence Livermore National Laboratory (US)
- Centre National de la Recherche Scientifique (FR)
- Planetary Science Institute (US)
- Goddard Space Flight Center (US)
- Georgia Institute of Technology (US)
- Jet Propulsion Laboratory (US)
- Parthenope University of Naples (IT)
- Université Côte d'Azur (FR)
- Arcetri Astrophysical Observatory (IT)
- Astronomical Observatory of Rome (IT)
- Agenzia Spaziale Italiana (IT)
- Trieste Astronomical Observatory (IT)
- Astronomical Observatory of Capodimonte (IT)
- Johns Hopkins University Applied Physics Laboratory (US)
- Nello Carrara Institute of Applied Physics (IT)
- Institute for Space Astrophysics and Planetology (IT)
- Observatoire de la Côte d’Azur (FR)
- Osservatorio Astronomico di Padova (IT)
- University of Maryland, College Park (US)
- University of Maryland, Baltimore County (US)
- International Space Science Institute (CH)
- University of Bologna (IT)
- Politecnico di Milano (IT)
Publication Details
- Journal
- The Planetary Science Journal
- Published
- 2025-07-01
- DOI
- https://doi.org/10.3847/psj/addd1a
- Citations
- 5
- Primary Topic
- Astro and Planetary Science
- Type
- article
- Field-Weighted Citation Impact
- 5.77
Funders
- National Aeronautics and Space Administration
- Agence Nationale de la Recherche
- Agenzia Spaziale Italiana