Momentum transfer from the DART mission kinetic impact on asteroid Dimorphos

Journal
Date Issued
2023
Author(s)
Cheng, Andrew F.
•
Agrusa, Harrison F.
•
Barbee, Brent W.
•
Meyer, Alex J.
•
Farnham, Tony L.
•
Raducan, Sabina D.
•
Richardson, Derek C.
•
•
•
•
Statler, Thomas S.
•
Chesley, Steven
•
Naidu, Shantanu P.
•
Hirabayashi, Masatoshi
•
Li, Jian-Yang
•
Eggl, Siegfried
•
Barnouin, Olivier S.
•
Chabot, Nancy L.
•
Chocron, Sidney
•
Collins, Gareth S.
•
Daly, R. Terik
•
Davison, Thomas M.
•
DeCoster, Mallory E.
•
Ernst, Carolyn M.
•
Ferrari, Fabio
•
Graninger, Dawn M.
•
Jacobson, Seth A.
•
Jutzi, Martin
•
Kumamoto, Kathryn M.
•
Luther, Robert
•
Lyzhoft, Joshua R.
•
Michel, Patrick
•
Murdoch, Naomi
•
Nakano, Ryota
•
Palmer, Eric
•
Rivkin, Andrew S.
•
Scheeres, Daniel J.
•
Stickle, Angela M.
•
Sunshine, Jessica M.
•
Trigo-Rodriguez, Josep M.
•
Vincent, Jean-Baptiste
•
Walker, James D.
•
Wünnemann, Kai
•
Zhang, Yun
•
Amoroso, Marilena
•
Bertini, Ivano
•
•
Capannolo, Andrea
•
•
•
Deshapriya, Prasanna J. D.
•
Gai, Igor
•
Hasselmann, Pedro H.
•
•
Impresario, Gabriele
•
Ivanovski, Stavro L.
•
Lavagna, Michèle
•
•
Epifani, Elena M.
•
Modenini, Dario
•
•
•
•
Pirrotta, Simone
•
•
Rossi, Alessandro
•
Tortora, Paolo
•
Zannoni, Marco
•
Zanotti, Giovanni
DOI
Abstract
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 26 September 2022 as a planetary defence test1. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defence, intended to validate kinetic impact as a means of asteroid deflection. Here we report a determination of the momentum transferred to an asteroid by kinetic impact. On the basis of the change in the binary orbit period2, we find an instantaneous reduction in Dimorphos's along-track orbital velocity component of 2.70 ± 0.10 mm s−1, indicating enhanced momentum transfer due to recoil from ejecta streams produced by the impact3,4. 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=3.61−0.25 +0.19(1 σ ) . These β values indicate that substantially 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.
Volume
616
Issue
7957
Start page
457
Uri
Url
Issn Identifier
0028-0836
Ads BibCode
2023Natur.616..457C
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

s41586-023-05878-z.pdf

Description
Pdf editoriale
Size

7.33 MB

Format

Adobe PDF

Checksum (MD5)

9ccfade5f02f42167222bf567ae8b8f2