Momentum Transfer from the DART Mission Kinetic Impact on Asteroid Dimorphos
Creators: name: Cheng, Andrew F.
name: Agrusa, Harrison F.
name: Barbee, Brent W.
name: Meyer, Alex J.
name: Farnham, Tony L.
name: Raducan, Sabina D.
name: Richardson, Derek C.
name: Dotto, Elisabetta
name: Zinzi, Angelo
name: Della Corte, Vincenzo
name: Statler, Thomas S.
name: Chesley, Steven
name: Naidu, Shantanu P.
name: Hirabayashi, Masatoshi
name: Li, Jian-Yang
name: Eggl, Siegfried
name: Barnouin, Olivier S.
name: Chabot, Nancy L.
name: Chocron, Sidney
name: Collins, Gareth S.
name: Daly, R. Terik
name: Davison, Thomas M.
name: DeCoster, Mallory E.
name: Ernst, Carolyn M.
name: Ferrari, Fabio
name: Graninger, Dawn M.
name: Jacobson, Seth A.
name: Jutzi, Martin
name: Kumamoto, Kathryn M.
name: Luther, Robert
name: Lyzhoft, Joshua R.
name: Michel, Patrick
name: Murdoch, Naomi
name: Nakano, Ryota
name: Palmer, Eric
name: Rivkin, Andrew S.
name: Scheeres, Daniel J.
name: Stickle, Angela M.
name: Sunshine, Jessica M.
name: Trigo-Rodriguez, Josep M.
name: Vincent, Jean-Baptiste
name: Walker, James D.
name: Wünnemann, Kai
name: Zhang, Yun
name: Amoroso, Marilena
name: Bertini, Ivano
name: Brucato, John R.
name: Capannolo, Andrea
name: Cremonese, Gabriele
name: Dall'Ora, Massimo
name: Deshapriya, Prasanna J. D.
name: Gai, Igor
name: Hasselmann, Pedro H.
name: Ieva, Simone
name: Impresario, Gabriele
name: Ivanovski, Stavro L.
name: Lavagna, Michèle
name: Lucchetti, Alice
name: Epifani, Elena M.
name: Modenini, Dario
name: Pajola, Maurizio
name: Palumbo, Pasquale
name: Perna, Davide
name: Pirrotta, Simone
name: Poggiali, Giovanni
name: Rossi, Alessandro
name: Tortora, Paolo
name: Zannoni, Marco
name: Zanotti, Giovanni
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on September 26, 2022 as a planetary defense test. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defense, intended to validate kinetic impact as a means of asteroid deflection. Here we report the first determination of the momentum transferred to an asteroid by kinetic impact. Based on the change in the binary orbit period, we find an instantaneous reduction in Dimorphos's along-track orbital velocity component of 2.70 +/- 0.10 mm/s, indicating enhanced momentum transfer due to recoil from ejecta streams produced by the impact. For a Dimorphos bulk density range of 1,500 to 3,300 kg/m$^3$, we find that the expected value of the momentum enhancement factor, $β$, ranges between 2.2 and 4.9, depending on the mass of Dimorphos. If Dimorphos and Didymos are assumed to have equal densities of 2,400 kg/m$^3$, $β$= 3.61 +0.19/-0.25 (1 $σ$). These $β$ values indicate that significantly more momentum was transferred to Dimorphos from the escaping impact ejecta than was incident with DART. Therefore, the DART kinetic impact was highly effective in deflecting the asteroid Dimorphos.
description: accepted by Nature