Orbital period change of Dimorphos due to the DART kinetic impact
Abstract
The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 minutes was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement ($\beta$) was possible. In the years prior to impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos. Here we report the change in the orbital period of Dimorphos as a result of the DART kinetic impact to be -33.0 +/- 1.0 (3$\sigma$) minutes. Using new Earth-based lightcurve and radar observations, two independent approaches determined identical values for the change in the orbital period. This large orbit period change suggests that ejecta contributed a significant amount of momentum to the asteroid beyond what the DART spacecraft carried.
Citation
Thomas , C A , Naidu , S P , Scheirich , P , Moskovitz , N A , Pravec , P , Chesley , S R , Rivkin , A S , Osip , D J , Lister , T A , Benner , L A M , Brozović , M , Contreras , C , Morrell , N , Rożek , A , Kušnirák , P , Hornoch , K , Mages , D , Taylor , P A , Seymour , A D , Snodgrass , C , Jørgensen , U G , Dominik , M , Skiff , B , Polakis , T , Knight , M M , Farnham , T L , Giorgini , J D , Rush , B , Bellerose , J , Salas , P , Armentrout , W P , Watts , G , Busch , M W , Chatelain , J , Gomez , E , Greenstreet , S , Phillips , L , Bonavita , M , Burgdorf , M J , Khalouei , E , Longa-Peña , P , Rabus , M , Sajadian , S , Chabot , N L , Cheng , A F , Ryan , W H , Ryan , E V , Holt , C E & Agrusa , H F 2023 , ' Orbital period change of Dimorphos due to the DART kinetic impact ' , Nature , vol. Accelerated article . https://doi.org/10.1038/s41586-023-05805-2
Publication
Nature
Status
Peer reviewed
ISSN
0028-0836Type
Journal article
Rights
Copyright © 2023, The Author(s), under exclusive licence to Springer Nature Limited. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1038/s41586-023-05805-2.
Description
Funding: U.G.J. acknowledges funding from the Novo Nordisk Foundation Interdisciplinary Synergy Programme grant no. NNF19OC0057374, and from the European Union H2020-MSCA-ITN-2019 grant no. 860470 (CHAMELEON). E.K. is supported by the National Research Foundation of Korea 2021M3F7A1082056. P.L.P. was partly funded by “Programa de Iniciación en Investigación-Universidad de Antofagasta. INI-17-03".Collections
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