{"id":9989,"date":"2016-09-22T23:52:51","date_gmt":"2016-09-22T21:52:51","guid":{"rendered":"http:\/\/karmaka.de\/?p=9989"},"modified":"2016-09-22T23:52:51","modified_gmt":"2016-09-22T21:52:51","slug":"global-variations-in-regolith-properties-on-asteroid-vesta-from-dawns-low-altitude-mapping-orbit","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=9989","title":{"rendered":"Global variations in regolith properties on asteroid Vesta from Dawn&#8217;s low-altitude mapping orbit."},"content":{"rendered":"<p>Denevi, B. W., Beck, A. W., Coman, E. I., Thomson, B. J., Ammannito, E., Blewett, D. T., Sunshine, J. M., De Sanctis, M. C., Li, J.-Y., Marchi, S., Mittlefehldt, D. W., Petro, N. E., Raymond, C. A. and Russell, C. T. (2016), <\/p>\n<p>Meteoritics &#038; Planetary Science. doi: 10.1111\/maps.12729<br \/>\nVersion of Record online: 22 SEP 2016<\/p>\n<p><a href=\"http:\/\/onlinelibrary.wiley.com\/wol1\/doi\/10.1111\/maps.12729\/abstract\" target=\"_blank\"><strong>LINK<\/strong><\/a><\/p>\n<p>&#8220;We investigate the depth, variability, and history of regolith on asteroid Vesta using data from the Dawn spacecraft. High-resolution (15\u201320 m pixel\u22121) Framing Camera images are used to assess the presence of morphologic indicators of a shallow regolith, including the presence of blocks in crater ejecta, spur-and-gully\u2013type features in crater walls, and the retention of small (<300 m) impact craters. Such features reveal that the broad, regional heterogeneities observed on Vesta in terms of albedo and surface composition extend to the physical properties of the upper ~1 km of the surface. Regions of thin regolith are found within the Rheasilvia basin and at equatorial latitudes from ~0\u201390\u00b0E and ~260\u2013360\u00b0E. Craters in these areas that appear to excavate material from beneath the regolith have more diogenitic (Rheasilvia, 0\u201390\u00b0E) and cumulate eucrite (260\u2013360\u00b0E) compositions. A region of especially thick regolith, where depths generally exceed 1 km, is found from ~100\u2013240\u00b0E and corresponds to heavily cratered, low-albedo surface with a basaltic eucrite composition enriched in carbonaceous chondrite material. The presence of a thick regolith in this area supports the idea that this is an ancient terrain that has accumulated a larger component of exogenic debris. We find evidence for the gardening of crater ejecta toward more howarditic compositions, consistent with regolith mixing being the dominant form of \u201cweathering\u201d on Vesta.\"\n<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Denevi, B. W., Beck, A. W., Coman, E. I., Thomson, B. J., Ammannito, E., Blewett, D. T., Sunshine, J. M., De Sanctis, M. C., Li, J.-Y., Marchi, S., Mittlefehldt, D. W., Petro, N. E., Raymond,&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,36,35,33,34,186],"tags":[359,1872],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/9989"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=9989"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/9989\/revisions"}],"predecessor-version":[{"id":9990,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/9989\/revisions\/9990"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9989"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9989"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9989"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}