Ejecta from the DART-produced active asteroid Dimorphos
Abstract
Some active asteroids have been proposed to be the result of impact events. Because active asteroids are generally discovered serendipitously only after their tail formation, the process of the impact ejecta evolving into a tail has never been directly observed. NASA's Double Asteroid Redirection Test (DART) mission, apart from having successfully changed the orbital period of Dimorphos, demonstrated the activation process of an asteroid from an impact under precisely known impact conditions. Here we report the observations of the DART impact ejecta with the Hubble Space Telescope (HST) from impact time T+15 minutes to T+18.5 days at spatial resolutions of ~2.1 km per pixel. Our observations reveal a complex evolution of ejecta, which is first dominated by the gravitational interaction between the Didymos binary system and the ejected dust and later by solar radiation pressure. The lowest-speed ejecta dispersed via a sustained tail that displayed a consistent morphology with previously observed asteroid tails thought to be produced by impact. The ejecta evolution following DART's controlled impact experiment thus provides a framework for understanding the fundamental mechanisms acting on asteroids disrupted by natural impact.
Cite
@article{arxiv.2303.01700,
title = {Ejecta from the DART-produced active asteroid Dimorphos},
author = {Jian-Yang Li and Masatoshi Hirabayashi and Tony L. Farnham and Jessica M. Sunshine and Matthew M. Knight and Gonzalo Tancredi and Fernando Moreno and Brian Murphy and Cyrielle Opitom and Steve Chesley and Daniel J. Scheeres and Cristina A. Thomas and Eugene G. Fahnestock and Andrew F. Cheng and Linda Dressel and Carolyn M. Ernst and Fabio Ferrari and Alan Fitzsimmons and Simone Ieva and Stavro L. Ivanovski and Teddy Kareta and Ludmilla Kolokolova and Tim Lister and Sabina D. Raducan and Andrew S. Rivkin and Alessandro Rossi and Stefania Soldini and Angela M. Stickle and Alison Vick and Jean-Baptiste Vincent and Harold A. Weaver and Stefano Bagnulo and Michele T. Bannister and Saverio Cambioni and Adriano Campo Bagatin and Nancy L. Chabot and Gabriele Cremonese and R. Terik Daly and Elisabetta Dotto and David A. Glenar and Mikael Granvik and Pedro H. Hasselmann and Isabel Herreros and Seth Jacobson and Martin Jutzi and Tomas Kohout and Fiorangela La Forgia and Monica Lazzarin and Zhong-Yi Lin and Ramin Lolachi and Alice Lucchetti and Rahil Makadia and Elena Mazzotta Epifani and Patrick Michel and Alessandra Migliorini and Nicholas A. Moskovitz and Jens Orm. and Maurizio Pajola and Paul S. nchez and Stephen R. Schwartz and Colin Snodgrass and Jordan Steckloff and Timothy J. Stubbs and Josep M. Trigo-Rodriguez},
journal= {arXiv preprint arXiv:2303.01700},
year = {2023}
}
Comments
accepted by Nature