{"id":8346,"date":"2014-07-18T01:49:43","date_gmt":"2014-07-18T05:49:43","guid":{"rendered":"http:\/\/hobbyspace.com\/Blog\/?p=8346"},"modified":"2014-07-18T01:49:43","modified_gmt":"2014-07-18T05:49:43","slug":"esas-rosetta-probe-nears-its-target-comet-and-finds-it-weirdly-shaped","status":"publish","type":"post","link":"https:\/\/hobbyspace.com\/Blog\/?p=8346","title":{"rendered":"ESA’s Rosetta probe nears its target comet and finds it weirdly shaped"},"content":{"rendered":"

The European Space Agency’s Rosetta<\/a>\u00a0<\/span>\u00a0probe was launched in March 2004 on an Ariane V rocket and on August 6th it will finally<\/p>\n

rendezvous with Comet 67P\/Churyumov-Gerasimenko and remain in close proximity to the icy nucleus as it plunges towards the warmer inner reaches of the Sun\u2019s domain. At the same time, a small lander will be released onto the surface of this mysterious cosmic iceberg.<\/span><\/em><\/p>\n

 <\/p>\n

Here is a post from the\u00a0Rosetta\u00a0blog<\/a>\u00a0about how the comet’s structure is starting to come into focus:<\/p>\n

The dual personality of comet 67P\/C-G\u00a0<\/a><\/strong><\/p>\n

This week\u2019s images of comet 67P\/Churyumov-Gerasimenko reveal an extraordinarily irregular shape. We had hints of that in last week\u2019s images and in the unscheduled previews that were seen a few days ago, and in that short time it has become clear that this is no ordinary comet. Like its name, it seems that comet 67P\/C-G is in two parts.<\/p>\n

\"Comet<\/a>Comet 67P\/C-G imaged on 14 July 2014 from a distance of approximately 12 000 km.<\/em>
\nCredits: ESA\/Rosetta\/MPS for <\/em>
\nOSIRIS Team MPS\/UPD\/LAM\/IAA\/SSO\/INTA\/UPM\/DASP\/IDA<\/em><\/p>\n

What the spacecraft is actually seeing is the pixelated image shown [above], which was taken by Rosetta\u2019s OSIRIS narrow angle camera on 14 July from a distance of 12 000 km.<\/p>\n

A second image and a movie show the comet after the image has been processed. The technique used, called \u201csub-sampling by interpolation\u201d, only acts to remove the pixelisation and make a smoother image, and it is important to note that the comet\u2019s surface features won\u2019t be as smooth as the processing implies. The surface texture has yet to be resolved simply because we are still too far away; any apparent brighter or darker regions may turn out to be false interpretations at this early stage.<\/p>\n

But the movie, which uses a sequence of 36 interpolated images each separated by 20 minutes, certainly provides a truly stunning 360-degree preview of the overall complex shape of the comet. Regardless of surface texture, we can certainly see an irregular shaped world shining through. Indeed, some people have already likened the shape to a duck, with a distinct body and head.<\/p>\n

Although less obvious in the \u2018real\u2019 image, the movie of interpolated images supports the presence of two definite components. One segment seems to be rather elongated, while the other appears more bulbous.<\/p>\n

\"Rotating
\n<\/a>Rotating view of comet 67P\/C-G on 14 July 2014.<\/em>
\n Credits: ESA\/Rosetta\/MPS for
\nOSIRIS Team MPS\/UPD\/LAM\/IAA\/SSO\/INTA\/UPM\/DASP\/IDA<\/em><\/p>\n

Dual objects like this \u2013 known as \u2018contact binaries\u2019 in comet and asteroid terminology \u2013 are not uncommon.<\/p>\n

Indeed,\u00a0comet 8P\/Tuttle<\/a>\u00a0is thought to be such a contact binary; radio imaging by the ground-based Arecibo telescope in Puerto Rico in 2008 suggested that it comprises two sphere-like objects. Meanwhile, the bone-shaped comet\u00a0103P\/Hartley 2<\/a>, imaged during NASA\u2019s EPOXI flyby in 2011, revealed a comet with two distinct halves separated by a smooth region. In addition, observations ofasteroid 25143 Itokawa<\/a>\u00a0by JAXA\u2019s Hayabusa mission, combined with ground-based data, suggest an asteroid comprising two sections of highly contrasting densities.<\/p>\n

Is Rosetta en-route to rendezvous with a similar breed of comet? The scientific rewards of studying such a comet would be high, as a number of possibilities exist as to how they form.<\/p>\n

One popular theory is that such an object could arise when two comets \u2013 even two compositionally distinct comets \u2013 melded together under a low velocity collision during the Solar System\u2019s formation billions of years ago, when small building blocks of rocky and icy debris coalesced to eventually create planets. Perhaps comet 67P\/C-G will provide a unique record of the physical processes of accretion.<\/p>\n

Or maybe it is the other way around \u2013 that is, a single comet could be tugged into a curious shape by the strong gravitational pull of a large object like Jupiter or the Sun; after all, comets are rubble piles with weak internal strength as directly witnessed in the fragmentation of comet Shoemaker-Levy 9 and the subsequent impacts into Jupiter, 20 years ago this week. Perhaps the two parts of comet 67P\/C-G will one day separate completely.<\/p>\n

On the other hand, perhaps comet 67P\/C-G may have once been a much rounder object that became highly asymmetric thanks to ice evaporation. This could have happened when the comet first entered the Solar System from the Kuiper Belt, or on subsequent orbits around the Sun.<\/p>\n

\"Comet<\/a><\/p>\n

Comet 67P\/C-G on 14 July 2014 \u2013 processed view. <\/em>
\nCredits: ESA\/Rosetta\/MPS for <\/em>
\nOSIRIS Team MPS\/UPD\/LAM\/IAA\/SSO\/INTA\/UPM\/DASP\/ID<\/em><\/p>\n

One could also speculate that the striking dichotomy of the comet\u2019s morphology is the result of a near catastrophic impact event that ripped out one side of the comet. Similarly, it is not unreasonable to think that a large outburst event may have weakened one side of the comet so much that it simply gave away, crumbling into space.<\/p>\n

But, while the interpolated images are certainly brilliant, we need to be closer still to see a better three-dimensional view \u2013 not to mention to perform a spectroscopic analysis to determine the comet\u2019s composition \u2013 in order to draw robust scientific conclusions about this exciting comet.<\/p>\n

Rosetta Mission Manager Fred Jansen comments: \u201cWe currently see images that suggest a rather complex cometary shape, but there is still a lot that we need to learn before jumping to conclusions. Not only in terms of what this means for comet science in general, but also regarding our planning for science observations, and the operational aspects of the mission such as orbiting and landing.<\/p>\n

\u201cWe will need to perform detailed analyses and modelling of the shape of the comet to determine how best we can fly around such a uniquely shaped body, taking into account flight control and astrodynamics, the science requirements of the mission, and the landing-related elements like landing site analysis and lander-to-orbiter visibility. But, with fewer than 10 000 km to go before the 6 August rendezvous, our open questions will soon be answered.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

The European Space Agency’s Rosetta\u00a0\u00a0probe was launched in March 2004 on an Ariane V rocket and on August 6th it will finally rendezvous with Comet 67P\/Churyumov-Gerasimenko and remain in close proximity to the icy nucleus as it plunges towards the warmer inner reaches of the Sun\u2019s domain. At the same time, a small lander will … Continue reading ESA’s Rosetta probe nears its target comet and finds it weirdly shaped<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[75,13],"tags":[],"class_list":["post-8346","post","type-post","status-publish","format-standard","hentry","category-asteroids","category-space-science"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p34aWK-2aC","jetpack-related-posts":[{"id":8579,"url":"https:\/\/hobbyspace.com\/Blog\/?p=8579","url_meta":{"origin":8346,"position":0},"title":"More Rosetta photos of comet 67P\/C-G","author":"TopSpacer","date":"August 14, 2014","format":false,"excerpt":"Rosetta\u00a0returns more great pictures of the comet\u00a0t 67P\/Churyumov-Gerasimenko:\u00a0 *\u00a0CometWatch \u2013 12 August | Rosetta - ESA's comet chaser Full-frame NAVCAM image taken on 12 August 2014 from a distance of about 103 km from comet 67P\/Churyumov-Gerasimenko. Credits: ESA\/Rosetta\/NAVCAM *\u00a0CometWatch \u2013 13 August | Rosetta - ESA's comet chaser Full-frame NAVCAM\u2026","rel":"","context":"In "Asteroids & Comets"","block_context":{"text":"Asteroids & Comets","link":"https:\/\/hobbyspace.com\/Blog\/?cat=75"},"img":{"alt_text":"Full-frame NAVCAM image taken on 12 August 2014 from a distance of about 103 km from comet 67P\/Churyumov-Gerasimenko. Credits: ESA\/Rosetta\/NAVCAM","src":"https:\/\/i0.wp.com\/blogs.esa.int\/rosetta\/files\/2014\/08\/ESA_ROSETTA_NAVCAM_20140812.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":8480,"url":"https:\/\/hobbyspace.com\/Blog\/?p=8480","url_meta":{"origin":8346,"position":1},"title":"Rosetta nears comet rendezvous","author":"TopSpacer","date":"August 5, 2014","format":false,"excerpt":"The European Space Agency's\u00a0Rosetta\u00a0spacecraft will rendezvous with \u00a0Comet 67P\/Churyumov-Gerasimenko on Wednesday. \u00a0Find lots of info, images, videos, etc of the approach and rendezvous at the webstie\u00a0Rosetta | rendevous with a comet. A livestream webcast will start on Wednesday at 08:00UTC (4:00 am EDT). \u00a0Here's the\u00a0Rosetta timeline\u00a0for events in this initial\u2026","rel":"","context":"In "Asteroids & Comets"","block_context":{"text":"Asteroids & Comets","link":"https:\/\/hobbyspace.com\/Blog\/?cat=75"},"img":{"alt_text":"Crop from the 3 August image of comet 67P\/Churyumov-Gerasimenko. Credits: ESA\/Rosetta\/NAVCAM","src":"https:\/\/i0.wp.com\/blogs.esa.int\/rosetta\/files\/2014\/08\/ESA_ROSETTA_NAVCAM_20140803_cropped_scaledx2.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":15915,"url":"https:\/\/hobbyspace.com\/Blog\/?p=15915","url_meta":{"origin":8346,"position":2},"title":"New animation of Rosetta images shows a wild time on Comet 67P","author":"TopSpacer","date":"April 26, 2018","format":false,"excerpt":"In 2014 the European Space Agency's\u00a0Rosetta\u00a0probe went into orbit around \u00a0Comet 67P\/Churyumov\u2013Gerasimenko\u00a0and spent a couple of years studying it.\u00a0 Jacint Roger Perez combined a series of 33 images made during a 25 minute period as the probe flew about 13 kilometers from the comet and the resulting time lapse creates\u2026","rel":"","context":"In "Asteroids & Comets"","block_context":{"text":"Asteroids & Comets","link":"https:\/\/hobbyspace.com\/Blog\/?cat=75"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/hobbyspace.com\/Blog\/wp-content\/uploads\/2018\/04\/RosettaOsirisC67P_JacintRoger1.gif?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":9759,"url":"https:\/\/hobbyspace.com\/Blog\/?p=9759","url_meta":{"origin":8346,"position":3},"title":"Video: Seminar on the Rosetta Lander (Philae) mission to comet 67P\/C-G","author":"TopSpacer","date":"January 26, 2015","format":false,"excerpt":"Here's a SETI Institute seminar by Jens Biele of the German space agency (DLR) in which he talks about the ESA Rosetta\/Philae\u00a0landing on\u00a0Comet 67P\/C-G:\u00a0The Rosetta Lander (PHILAE) mission: landing on comet 67P\/Churyumov-Gerasimenko -\u00a0SETI Institute http:\/\/youtu.be\/tQLtAp1Aw48 Here is the caption to the video: The Rosetta Lander (PHILAE) mission: landing on comet\u2026","rel":"","context":"In "Asteroids & Comets"","block_context":{"text":"Asteroids & Comets","link":"https:\/\/hobbyspace.com\/Blog\/?cat=75"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/img.youtube.com\/vi\/tQLtAp1Aw48\/0.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":10363,"url":"https:\/\/hobbyspace.com\/Blog\/?p=10363","url_meta":{"origin":8346,"position":4},"title":"Rosetta montage of images of Comet 67P\/C-G","author":"TopSpacer","date":"April 13, 2015","format":false,"excerpt":"The\u00a0ESA Rosetta\u00a0mission releases a new set of images of Comet 67P\/Churyumov-Gerasimenko: Comet activity 31 January \u2013 25 March 2015 Click for larger image Four months from today, on 13 August, Comet 67P\/Churyumov-Gerasimenko will reach perihelion \u2013 a moment that defines its closest point to the Sun along its orbit. 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Most of the images require 3-D glasses but here is\u00a0a fly-over version: https:\/\/www.youtube.com\/watch?v=mAgHY-hDq9c Here is one for your glasses: https:\/\/www.youtube.com\/watch?v=AebfoQyLiY0 For many more images, go\u2026","rel":"","context":"In "Asteroids & Comets"","block_context":{"text":"Asteroids & Comets","link":"https:\/\/hobbyspace.com\/Blog\/?cat=75"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/img.youtube.com\/vi\/mAgHY-hDq9c\/0.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=\/wp\/v2\/posts\/8346","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8346"}],"version-history":[{"count":1,"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=\/wp\/v2\/posts\/8346\/revisions"}],"predecessor-version":[{"id":8347,"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=\/wp\/v2\/posts\/8346\/revisions\/8347"}],"wp:attachment":[{"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8346"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8346"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hobbyspace.com\/Blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8346"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}