{"id":11129,"date":"2013-10-23T08:46:00","date_gmt":"2013-10-23T18:46:00","guid":{"rendered":"http:\/\/darkerview.com\/wordpress\/wp-content\/uploads\/2013\/10\/HubbleISON20131009.jpg"},"modified":"2013-10-23T08:46:00","modified_gmt":"2013-10-23T18:46:00","slug":"hubbleison20131009","status":"inherit","type":"attachment","link":"https:\/\/darkerview.com\/wordpress\/?attachment_id=11129","title":{"rendered":"Comet C\/2012 S1 ISON"},"author":1,"comment_status":"open","ping_status":"closed","template":"","meta":[],"jetpack_sharing_enabled":true,"description":{"rendered":"

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

The photographic proof is in: Reports of Comet ISON\u2019s demise were greatly exaggerated. Contrary to some pessimistic predictions, new Hubble data show the comet still trucking along as it falls inward of Mars and ever closer toward the Sun.<\/p>\n

This new image, recorded by Hubble on October 9, combines long exposures taken through blue and red filters. Over 29 minutes, Hubble switched back and forth between these filters as it tracked Comet ISON across the sky.<\/p>\n

What little color ISON has is due to differences between a comet\u2019s coma and its tail. The tail, comprised of dust particles torn away from the comet by the gentle pressure of sunlight, appears redder because dust grains reflect redder light. The coma, by contrast, is bluer. It doesn\u2019t contain much dust, just gas sublimating from the comet\u2019s surface.<\/p>\n

The comet\u2019s nucleus, estimated at less than 2 kilometers in diameter, is tiny even through Hubble\u2019s eagle eyes. A single pixel in this image spans 55 km of comet, making the nucleus un-resolvable at this separation (about twice the Earth-Sun distance). Still, careful study of this image suggests the nucleus is almost certainly still intact \u2014 the coma spreads out evenly from a single point, which we wouldn\u2019t see if ISON were falling to pieces.<\/p>\n

In fact, the symmetry of ISON\u2019s coma suggests that the comet\u2019s entire Sun-facing surface is feeding the coma \u2014 no jets of gas have been spotted in this image. Without a jet to spin it around (see: WALL-E & Gravity, \u201cfire extinguisher\u201d) ISON likely isn\u2019t rotating much. This suggests an exciting potential future: Perhaps there\u2019s a \u201cdark\u201d side of ISON, which won\u2019t have ever seen the light of day until the comet goes around the Sun. If such pristine material still exists, ISON may become more active than we currently expect.<\/p>\n

One mystery remains. How has ISON \u2014 humble, patient, surprisingly average Comet ISON \u2014 sparked predictions that run the gamut from \u201cbright as the full moon\u201d to \u201cdisintegrating as we speak\u201d? Simply put, ISON peaked early. When it was first discovered, way out past Jupiter, ISON was really bright. Extrapolated, those first data points made ISON look like it would shine even more as it got closer \u2014 and when it didn\u2019t, the coverage seesawed back toward calling ISON a total bust. <\/p>\n

According the University of Maryland\u2019s Mike A\u2019Hearn, that\u2019s the curse of \u201cdynamically new\u201d comets, including the infamous Kohoutek. In the first four billion years of its life, ISON never once strayed into the protective umbrella of the solar wind. Without that protection, the comet\u2019s surface was bombarded by galactic cosmic rays: high-energy particles from exotic places like the rims of black holes. That irradiated surface became fragile, volatile \u2014 only a little heat from the Sun was enough to sublimate a huge amount of gas, causing ISON\u2019s brightness to spike early on. This is just one interpretation \u2014 Karen Meech from the University of Hawaii argues that an outburst of carbon monoxide better explains that early brightness \u2014 but the consequences still stand. ISON, like a burnt-out former child actor, has been unfairly judged by the benchmark of its own prodigious standard.<\/p>\n

Credit: NASA, ESA, and the Hubble Heritage Team<\/p>\n"},"caption":{"rendered":"

An image of comet C\/2012 S1 ISON acquired by the Hubble Space Telescope on October 9th, 2013, credit: NASA, ESA, and the Hubble Heritage Team<\/p>\n"},"alt_text":"Comet C\/2012 S1 ISON","media_type":"image","mime_type":"image\/jpeg","media_details":{"width":740,"height":720,"file":"2013\/10\/HubbleISON20131009.jpg","sizes":{"thumbnail":{"file":"HubbleISON20131009-150x150.jpg","width":150,"height":150,"mime_type":"image\/jpeg","source_url":"https:\/\/darkerview.com\/wordpress\/wp-content\/uploads\/2013\/10\/HubbleISON20131009-150x150.jpg"},"medium":{"file":"HubbleISON20131009-600x583.jpg","width":600,"height":583,"mime_type":"image\/jpeg","source_url":"https:\/\/darkerview.com\/wordpress\/wp-content\/uploads\/2013\/10\/HubbleISON20131009-600x583.jpg"},"full":{"file":"HubbleISON20131009.jpg","width":740,"height":720,"mime_type":"image\/jpeg","source_url":"https:\/\/darkerview.com\/wordpress\/wp-content\/uploads\/2013\/10\/HubbleISON20131009.jpg"}},"image_meta":{"aperture":0,"credit":"","camera":"","caption":"","created_timestamp":0,"copyright":"","focal_length":0,"iso":0,"shutter_speed":0,"title":""}},"post":11139,"source_url":"https:\/\/darkerview.com\/wordpress\/wp-content\/uploads\/2013\/10\/HubbleISON20131009.jpg","_links":{"self":[{"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/media\/11129"}],"collection":[{"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/media"}],"about":[{"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/attachment"}],"author":[{"embeddable":true,"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=11129"}]}}