{"id":22567,"date":"2017-03-22T07:49:09","date_gmt":"2017-03-22T07:49:09","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=22567"},"modified":"2017-03-22T07:49:46","modified_gmt":"2017-03-22T07:49:46","slug":"comet-67p","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2017\/03\/22\/comet-67p\/","title":{"rendered":"Comet 67P: a large landslide on another world"},"content":{"rendered":"
Comet 67P: a large landslide on another world<\/h5>\n

In a paper published in the journal Nature Astronomy (Pajola et al.<\/em> 2017<\/a>), Maurizio Pajola and a cost of dozens have recorded a large rockfall event occurring on Comet 67P \/ Churyumov-Gerasimenko.\u00a0 This event was recorded by the European Space Agency’s Rosetta mission over the period between 2014 and 2015.<\/p>\n

The event started when, in September 2014, the team spotted a large (70 m long) fracture at the top of a cliff now known as Aswan:-<\/p>\n

\"Comet

The rockslope failure on Comet 67P as revealed by the Rosetta mission, from Pajola et al.<\/em> (2017)<\/a>. Images d and e show the fracture, image f shows the post-failure scarp<\/p><\/div>\n

.<\/p>\n

Pajola et al.<\/em> (2017)<\/a> report that on 10th July 2015 Rosetta captured a large plume of dust emanating from this area; and on 15th July 2015 a new image of Comet 67P showed that the rock slope had collapsed.<\/p>\n

The volume of the rockfall is estimated to have been about 22,000 cubic metres, from a cliff that is 134 metres high.\u00a0 Before and after images of the rockfall site reveal an arcuate scar and a boulder field below:<\/p>\n

\"Comet

Pre- (a and b) and post- (c) failure images of the Aswan cliff collapse on Comet 67P, from Pajola et al.<\/em> (2017)<\/a><\/p><\/div>\n

.<\/p>\n

Pajola et al.<\/em> (2017)<\/a> suggest that that collapse was driven by thermal changes in the rock mass, which is considered to be deeply fractured, as Comet 67P moved closer to the sun.\u00a0 However, the actual failure occurred at night, when the calculated thermal gradients were low.\u00a0 I wonder therefore if this is the first time that progressive failure has been observed on another body in the solar system?<\/p>\n

In astronomical terms, the main interest here is that the rockfall mechanism provides an explanation for the outbursts of dust that have been observed to issue from the surface of Comet 67P.<\/p>\n

Reference<\/h5>\n

Pajola, M. et al. 2017.<\/i> The pristine interior of comet 67P revealed by the combined Aswan outburst and cliff collapse<\/a>. Nature Astrononmy<\/i> 1,<\/b> 0092 (2017).<\/p>\n","protected":false},"excerpt":{"rendered":"

In a paper just published in Nature Astronomy, Pajola et al (2017) describe a 22,000 cubic metre rockfall on Comet 67P, observed by the ESA Rosetta Mission <\/p>\n","protected":false},"author":22,"featured_media":22594,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[3009,3004,469,898,56,894],"class_list":["post-22567","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-landslide-report","tag-astronomy","tag-comet","tag-featured","tag-planet","tag-rockfall","tag-space"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/22567","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/comments?post=22567"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/22567\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/22594"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=22567"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=22567"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=22567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}