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Excavating Stickney crater at Phobos
Author(s) -
Bruck Syal Megan,
Rovny Jared,
Owen J. Michael,
Miller Paul L.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl070749
Subject(s) - impact crater , geology , terrain , mars exploration program , astrobiology , impact structure , ephemeral key , physics , geography , cartography , algorithm , computer science
Stickney crater, at 9 km across, dominates the morphology of ~22 km Phobos, the larger of the two moons of Mars. The Stickney impact event had global repercussions for Phobos, including extensive resurfacing and fracturing of the moon. Understanding the initial conditions and dynamical consequences of the collision is necessary to test competing hypotheses for the origin of peculiar grooved terrain that striates much of the surface. Previous modeling of the impact event was unable to replicate Stickney without globally fragmenting the satellite. Here we describe high‐resolution numerical simulations that successfully generate Stickney crater while maintaining the large‐scale structure of Phobos. Target porosity, which is estimated to be significant, aids in keeping the moon intact. Damage follows patterns centered on Stickney that are inconsistent with the observed alignment of grooved terrain on Phobos. Low‐velocity boulders are ejected at shallow angles in sufficient numbers to support a rolling‐boulder origin for grooved terrain.