          APOD: 2017 November 13 - Comet Machholz Approaches the Sun

                         Astronomy Picture of the Day

    Discover the cosmos! [1] Each day a different image or photograph of our
 fascinating universe is featured, along with a brief explanation written by a
                           professional astronomer.

                               2017 November 13
                                      [2]
                      Comet Machholz Approaches the Sun
  Image Credit: NASA [3] , SOHO [4] , LASCO [5] , Barbara Thompson [6] (NASA's
                                  GSFC [7] )

Explanation: Why is Comet Maccholz so depleted of carbon-containing chemicals?
Comet 96P/Machholz [8] 's original fame derives from its getting closer to the
Sun than any other short period comet -- half as close as Mercury [9]  -- and
doing so every five years. To better understand this unusual comet, NASA's
Sun-monitoring SOHO spacecraft [10]  tracked the comet during its latest
approach to the Sun [11]  in October. The featured image composite [12]  shows
the tail-enhanced comet swooping past the Sun. The Sun's bright surface is
hidden from view behind a dark occulter, although parts of the Sun's extended
corona [13]  are visible. Neighboring stars dot the background. One hypothesis
holds that these close solar approaches somehow cause Comet Machholz [14]  to
shed its carbon [15] , while another hypothesis posits that the comet formed
with this composition [16] far away -- possibly even in another star system
[17] .

          Free APOD Lectures: January 5 in NYC & January 9 in DC [18]
                    Tomorrow's picture: dust cluster [19]

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    Authors & editors: Robert Nemiroff [31] (MTU [32] ) & Jerry Bonnell [33]
                                  (UMCP [34] )
          NASA Official:  Phillip Newman Specific rights apply [35] .
              NASA Web Privacy Policy and Important Notices [36]
              A service of: ASD [37]  at NASA [38]  / GSFC [39]
                           & Michigan Tech. U. [40]
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Site notes:
  [1] archivepix.html
  [2] image/1711/CometMachholz2017_SOHO_big.mp4
  [3] https://www.nasa.gov/
  [4] https://sohowww.nascom.nasa.gov/about/about.html
  [5] http://star.mpae.gwdg.de/
  [6] https://science.gsfc.nasa.gov/sed/bio/barbara.j.thompson
  [7] https://www.nasa.gov/goddard
  [8] https://en.wikipedia.org/wiki/96P/Machholz
  [9] https://solarsystem.nasa.gov/planets/mercury
  [10] https://en.wikipedia.org/wiki/Solar_and_Heliospheric_Observatory
  [11] ap151102.html
  [12]
https://eitv3.deviantart.com/art/
Comet-Macholz-transit-2017-10-27-to-2017-10-29-712667342
  [13] ap170920.html
  [14] https://www.space.com/6184-odd-comet-possibly-star-system.html
  [15] http://periodic.lanl.gov/6.shtml
  [16] http://adsabs.harvard.edu/abs/2008AJ....136.2204S
  [17] ap171103.html
  [18] http://asterisk.apod.com/viewtopic.php?f=28&t=37750
  [19] ap171114.html
  [20] ap171112.html
  [21] archivepix.html
  [22] lib/apsubmit2015.html
  [23] lib/aptree.html
  [24] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  [25] calendar/allyears.html
  [26] /apod.rss
  [27] lib/edlinks.html
  [28] lib/about_apod.html
  [29] http://asterisk.apod.com/discuss_apod.php?date=171113
  [30] ap171114.html
  [31] http://www.phy.mtu.edu/faculty/Nemiroff.html
  [32] http://www.phy.mtu.edu/
  [33] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  [34] http://www.astro.umd.edu/
  [35] lib/about_apod.html#srapply
  [36] https://www.nasa.gov/about/highlights/HP_Privacy.html
  [37] https://astrophysics.gsfc.nasa.gov/
  [38] https://www.nasa.gov/
  [39] https://www.nasa.gov/centers/goddard/
  [40] http://www.mtu.edu/
