收藏 Collections from websites

 

Almost Three Tails for Comet Encke

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.

 

February 20, 2017

via NASA

Get a beautiful photo from NASA delivered to your email every day

猜您喜欢

This entry was posted on Tuesday, February 21st, 2017 at 3:56 am and is filed under 科学. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.




Add Comment

Leave a Reply

Comment Rules

  • Example Rule 1
  • Comment rule 2
  • 3. Bold Rule
  • more...

Copyright ©2017 收藏.