Orbital period change of Dimorphos due to the DART kinetic impact

0574031 - ASÚ 2024 RIV GB eng J - Journal Article
Thomas, Ch. - Naidu, S.P. - Scheirich, Peter - Moskovitz, N. A. - Pravec, Petr - Kušnirák, Peter - Hornoch, Kamil … Total 48 authors
Orbital period change of Dimorphos due to the DART kinetic impact.
Nature. Roč. 616, č. 7957 (2023), s. 448-451. ISSN 0028-0836. E-ISSN 1476-4687
R&D Projects: GA ČR(CZ) GA20-04431S
Grant - others:GA MŠk(CZ) LM2015042
Institutional support: RVO:67985815
Keywords : astrophysics * Earth and planetary astrophysics * double asteroid redirection test
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 64.8, year: 2022
Method of publishing: Open access

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 min was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision1, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement (β) was possible2,3. In the years before impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos4-6. 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 (3σ) min. 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 substantial amount of momentum to the asteroid beyond what the DART spacecraft carried.

Permanent Link: https://hdl.handle.net/11104/0344392