Tracking low-velocity ejecta from the DART impact on Dimorphos
Abstract
The DART impact on Dimorphos produced a large population of low-velocity ejecta (v < vesc), likely containing most of the excavated mass, whose early fate remains poorly constrained. We investigate the first 22 h evolution of ejecta launched at 1-9 cm/s and assess how orbital dynamics and surface transport after first contact shape the surface distribution of the re-accreted ejecta blanket. We use RAVEL, a model that couples three-dimensional orbital dynamics in the Didymos-Dimorphos system with surface transport on a digital terrain model, including detachment, re-impact, rebound, and frictional sliding. Re-accretion is rapid and asymmetric: more than 99% of the re-accreted mass returns to Dimorphos within 5 h. The slowest ejecta remain concentrated near the DART crater and dominate the primary ejecta blanket, whereas faster particles undergo orbital transport and preferentially populate antipodal and trailing regions. Surface motion strongly modifies the first-contact pattern, and the DART-derived rough terrain model produces elongated, topographically channelled depositional streaks dominated by the slowest ejecta, giving rise to a ray-like pattern. These results provide testable predictions for ESA's Hera mission and link ejecta-blanket morphology to orbital dynamics, re-accretion, and surface topography.
Related
- Post-DART impact ejecta re-accumulation on Dimorphos and implications for Hera gravity measurements
- Post-DART impact ejecta re-accumulation on Dimorphos and implications for Hera gravity measurements
- Dynamical evolution and surface accretion of DART impact ejecta in the (65803) Didymos system
- Numerical study of multiple scattering intensities obtained from dust grains of different sizes and compositions in an impact-induced ejecta curtain
- Impact of Gaia-Sausage-Enceladus Debris on Milky Way Escape-velocity Estimates in TNG50
BibTeX
@misc{herreros2026tracking,
title = {{Tracking low-velocity ejecta from the DART impact on Dimorphos}},
author = {Isabel Herreros and Sébastien Charnoz},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.15459},
eprint = {2606.15459},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.15459},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Tracking low-velocity ejecta from the DART impact on Dimorphos
AU - Isabel Herreros
AU - Sébastien Charnoz
PY - 2026
DA - 2026/10/04
PB - arXiv
DO - 10.48550/arxiv.2606.15459
UR - https://arxiv.org/abs/2606.15459
AB - The DART impact on Dimorphos produced a large population of low-velocity ejecta (v < vesc), likely containing most of the excavated mass, whose early fate remains poorly constrained. We investigate the first 22 h evolution of ejecta launched at 1-9 cm/s and assess how orbital dynamics and surface transport after first contact shape the surface distribution of the re-accreted ejecta blanket. We use RAVEL, a model that couples three-dimensional orbital dynamics in the Didymos-Dimorphos system with surface transport on a digital terrain model, including detachment, re-impact, rebound, and frictional sliding. Re-accretion is rapid and asymmetric: more than 99% of the re-accreted mass returns to Dimorphos within 5 h. The slowest ejecta remain concentrated near the DART crater and dominate the primary ejecta blanket, whereas faster particles undergo orbital transport and preferentially populate antipodal and trailing regions. Surface motion strongly modifies the first-contact pattern, and the DART-derived rough terrain model produces elongated, topographically channelled depositional streaks dominated by the slowest ejecta, giving rise to a ray-like pattern. These results provide testable predictions for ESA's Hera mission and link ejecta-blanket morphology to orbital dynamics, re-accretion, and surface topography.
ER -