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.

arXiv commentaccepted by Nature

References in corpus (18)

• Successful Kinetic Impact into an Asteroid for Planetary Defense
• Orbital Period Change of Dimorphos Due to the DART Kinetic Impact
• A collision in 2009 as the origin of the debris trail of asteroid P/2010 A2
• The Extraordinary Multi-Tailed Main-Belt Comet P/2013 P5
• Image Enhancement Techniques for Quantitative Investigations of Morphological Features in Cometary Comae: A Comparative Study
• Ejecta Cloud from a Kinetic Impact on the Secondary of a Binary Asteroid: I. Mechanical Environment and Dynamic Model
• P/2010A2 LINEAR - I: An impact in the Asteroid Main Belt
• Influence of the projectile geometry on the momentum transfer from a kinetic impactor and implications for the DART mission
• The Sporadic Activity of (6478) Gault: A YORP-driven event?
• Episodic Ejection from Active Asteroid 311P/PANSTARRS
• Episodically Active Asteroid 6478 Gault
• New Photometric Calibration of the Wide Field Camera 3 Detectors
• Anisotropic Ejection from Active Asteroid P/2010 A2: An Implication of Impact Shattering on an Asteroid
• Lofting of low speed ejecta produced in the DART experiment and production of a dust cloud
• Experimental phase functions of mm-sized cosmic dust grains
• The Asteroid-Comet Continuum
• Pattern of Impact-Induced Ejecta from Granular Targets with Large Inclusions
• Hubble Space Telescope Observations of Comet 9P/Tempel 1 during the Deep Impact Encounter

Cited by in corpus (15)

• Momentum Transfer from the DART Mission Kinetic Impact on Asteroid Dimorphos
• Physical properties of asteroid Dimorphos as derived from the DART impact
• Light Curves and Colors of the Ejecta from Dimorphos after the DART Impact
• The Dimorphos Boulder Swarm
• The Dynamical State of the Didymos System Before and After the DART Impact
• Lessons learned from NASA's DART impact about disrupting rubble-pile asteroids
• Rapid formation of binary asteroid systems post rotational failure: a recipe for making atypically shaped satellites
• Recurring Activity Discovered on Quasi-Hilda 2009 DQ118
• High-Speed Boulders and the Debris Field in DART Ejecta
• Delivery of DART Impact Ejecta to Mars and Earth: Opportunity for Meteor Observations
• Thermal and Optical Characterization of Near-Earth Objects: Science Commissioning of the Recently Upgraded Mid-Infrared Camera MIRSI on the NASA Infrared Telescope Facility
• ASTERIA -- Thermal Inertia Evaluation of asteroid Didymos
• Secondary impact debris in the Didymos system: what could be observed by Hera?
• Force chains bias the dynamic response to impacts in rubble-pile asteroids
• Numerical study of multiple scattering intensities obtained from dust grains of different sizes and compositions in an impact-induced ejecta curtain