An experimental study of low-velocity impacts into granular material in reduced gravity

Naomi Murdoch, Iris Avila Martinez, Cecily Sunday, Emmanuel Zenou, Olivier Cherrier, Alexandre Cadu, Yves Gourinat
(Submitted on 20 Feb 2017)

In order to improve our understanding of landing on small bodies and of asteroid evolution, we use our novel drop tower facility to perform low-velocity (2-40 cm s^-1), shallow impact experiments of a 10 cm diameter aluminum sphere into quartz sand in low effective gravities (~0.2-1 m s^-2). Using in situ accelerometers, we measure the acceleration profile during the impacts and determine the peak accelerations, collision durations and maximum penetration depth. We find that the penetration depth scales linearly with the collision velocity but is independent of the effective gravity for the experimental range tested, and that the collision duration is independent of both the effective gravity and the collision velocity. No rebounds are observed in any of the experiments. Our low-gravity experimental results indicate that the transition from the quasi-static regime to the inertial regime occurs for impact energies two orders of magnitude smaller than in similar impact experiments under terrestrial gravity. The lower energy regime change may be due to the increased hydrodynamic drag of the surface material in our experiments, but may also support the notion that the quasi-static regime reduces as the effective gravity becomes lower.

Comments:    Advance Access publication: January 4 2017
Subjects:    Earth and Planetary Astrophysics (astro-ph.EP); Soft Condensed Matter (cond-mat.soft); Geophysics (physics.geo-ph)
DOI:    10.1093/mnras/stw3391
Cite as:    arXiv:1702.05980 [astro-ph.EP]
     (or arXiv:1702.05980v1 [astro-ph.EP] for this version)
Submission history
From: Naomi Murdoch 
[v1] Mon, 20 Feb 2017 14:26:55 GMT (1468kb,D)
http://xxx.lanl.gov/abs/1702.05980