by APOD Robot » Mon Feb 20, 2017 5:07 am
Almost Three Tails for Comet Encke
Explanation: How can a comet have three tails? Normally, a comet has
two tails: an
ion tail of charged particles emitted by the comet and pushed out by the wind from the Sun, and a
dust tail of small debris that orbits behind the comet but is also pushed out, to some degree, by the solar wind. Frequently a comet will appear to have only
one tail because the other tail is not easily visible from the Earth. In the
featured unusual image,
Comet 2P/Encke appears to have
three tails because the ion tail split just near to the time when the image was taken. The complex solar wind is occasionally
turbulent and sometimes creates
unusual structure in an ion tail. On rare occasions even
ion-tail disconnection events have been recorded. An image of the Comet Encke taken two days later gives a perhaps
less perplexing perspective.
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[url=https://apod.nasa.gov/apod/ap170220.html][img]https://apod.nasa.gov/apod/calendar/S_170220.jpg[/img] [size=150]Almost Three Tails for Comet Encke[/size][/url]
[b] Explanation: [/b] How can a comet have three tails? Normally, a comet has [url=https://en.wikipedia.org/wiki/Comet_tail#/media/File:Cometorbit01.svg]two tails[/url]: an [url=https://pds.jpl.nasa.gov/planets/captions/smallbod/haltail.htm]ion tail[/url] of charged particles emitted by the comet and pushed out by the wind from the Sun, and a [url=http://hubblesite.org/reference_desk/faq/answer.php.id=19&cat=solarsystem]dust tail[/url] of small debris that orbits behind the comet but is also pushed out, to some degree, by the solar wind. Frequently a comet will appear to have only [url=https://apod.nasa.gov/apod/ap131117.html]one tail[/url] because the other tail is not easily visible from the Earth. In the [url=https://www.flickr.com/photos/fhhemmerich/32923225095/in/pool-3084377@N22/]featured unusual image[/url], [url=https://en.wikipedia.org/wiki/Comet_Encke]Comet 2P/Encke[/url] appears to have [i] three [/i] tails because the ion tail split just near to the time when the image was taken. The complex solar wind is occasionally [url=https://en.wikipedia.org/wiki/Turbulence]turbulent[/url] and sometimes creates [url=https://apod.nasa.gov/apod/ap020515.html]unusual[/url] [url=https://apod.nasa.gov/apod/ap020318.html]structure[/url] in an ion tail. On rare occasions even [url=https://apod.nasa.gov/apod/ap071003.html]ion-tail disconnection event[/url]s have been recorded. An image of the Comet Encke taken two days later gives a perhaps [url=http://www.damianpeach.com/deepsky/2p_encke_2017_02_16dp.jpg]less perplexing perspective[/url].
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