Light Curves and Colors of the Ejecta from Dimorphos after the DART Impact

Abstract

On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, a satellite of the asteroid 65803 Didymos. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In nominal cases, pre-impact predictions of the orbital period reduction ranged from ~8.8 - 17.2 minutes. Here we report optical observations of Dimorphos before, during and after the impact, from a network of citizen science telescopes across the world. We find a maximum brightening of 2.29 $\pm$ 0.14 mag upon impact. Didymos fades back to its pre-impact brightness over the course of 23.7 $\pm$ 0.7 days. We estimate lower limits on the mass contained in the ejecta, which was 0.3 - 0.5% Dimorphos' mass depending on the dust size. We also observe a reddening of the ejecta upon impact.

Accepted by Nature

References in corpus (5)

• Successful Kinetic Impact into an Asteroid for Planetary Defense
• Momentum Transfer from the DART Mission Kinetic Impact on Asteroid Dimorphos
• Ejecta from the DART-produced active asteroid Dimorphos
• Predictions for the Dynamical States of the Didymos System before and after the Planned DART Impact
• RGB photometric calibration of 15 million Gaia stars

Cited by in corpus (9)

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• Photometry of Type II Supernova SN 2023ixf with a Worldwide Citizen Science Network
• High-Speed Boulders and the Debris Field in DART Ejecta
• ASTERIA -- Thermal Inertia Evaluation of asteroid Didymos
• Simulation of Impact-induced seismic shaking on asteroid (25143) Itokawa to address its resurfacing process
• Secondary impact debris in the Didymos system: what could be observed by Hera?