TY - JOUR
T1 - Lobate and flow-like features on asteroid Vesta
AU - Williams, David
AU - O'Brien, David P.
AU - Schenk, Paul M.
AU - Denevi, Brett W.
AU - Carsenty, Uri
AU - Marchi, Simone
AU - Scully, Jennifer E C
AU - Jaumann, Ralf
AU - De Sanctis, Maria Cristina
AU - Palomba, Ernesto
AU - Ammannito, Eleonora
AU - Longobardo, Andrea
AU - Magni, Gianfranco
AU - Frigeri, Alessandro
AU - Russell, Christopher T.
AU - Raymond, Carol A.
AU - Davison, Thomas M.
N1 - Publisher Copyright:
© 2013 Elsevier Ltd. All rights reserved.
PY - 2014/11/15
Y1 - 2014/11/15
N2 - We studied high-resolution images of asteroid Vesta's surface (~70 and 20-25 m/pixel) obtained during the High- and Low-Altitude Mapping Orbits (HAMO, LAMO) of NASA's Dawn mission to assess the formation mechanisms responsible for a variety of lobate, flow-like features observed across the surface. We searched for evidence of volcanic flows, based on prior mathematical modeling and the well-known basaltic nature of Vesta's crust, but no unequivocal morphologic evidence of ancient volcanic activity has thus far been identified. Rather, we find that all lobate, flow-like features on Vesta appear to be related either to impact or erosional processes. Morphologically distinct lobate features occur in and around impact craters, and most of these are interpreted as impact ejecta flows, or possibly flows of impact melt. Estimates of melt production from numerical models and scaling laws suggests that large craters like Marcia (~60 km diameter) could have potentially produced impact melt volumes ranging from tens of millions of cubic meters to a few tens of cubic kilometers, which are relatively small volumes compared to similar-sized lunar craters, but which are consistent with putative impact melt features observed in Dawn images. There are also examples of lobate flows that trend downhill both inside and outside of crater rims and basin scarps, which are interpreted as the result of gravity-driven mass movements (slumps and landslides).
AB - We studied high-resolution images of asteroid Vesta's surface (~70 and 20-25 m/pixel) obtained during the High- and Low-Altitude Mapping Orbits (HAMO, LAMO) of NASA's Dawn mission to assess the formation mechanisms responsible for a variety of lobate, flow-like features observed across the surface. We searched for evidence of volcanic flows, based on prior mathematical modeling and the well-known basaltic nature of Vesta's crust, but no unequivocal morphologic evidence of ancient volcanic activity has thus far been identified. Rather, we find that all lobate, flow-like features on Vesta appear to be related either to impact or erosional processes. Morphologically distinct lobate features occur in and around impact craters, and most of these are interpreted as impact ejecta flows, or possibly flows of impact melt. Estimates of melt production from numerical models and scaling laws suggests that large craters like Marcia (~60 km diameter) could have potentially produced impact melt volumes ranging from tens of millions of cubic meters to a few tens of cubic kilometers, which are relatively small volumes compared to similar-sized lunar craters, but which are consistent with putative impact melt features observed in Dawn images. There are also examples of lobate flows that trend downhill both inside and outside of crater rims and basin scarps, which are interpreted as the result of gravity-driven mass movements (slumps and landslides).
KW - Asteroids
KW - Dawn
KW - Impact cratering
KW - Vesta
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U2 - 10.1016/j.pss.2013.06.017
DO - 10.1016/j.pss.2013.06.017
M3 - Article
AN - SCOPUS:84908254384
SN - 0032-0633
VL - 103
SP - 24
EP - 35
JO - Planetary and Space Science
JF - Planetary and Space Science
ER -