What are comets?
Comets In Depth
It is the website NASA, on the search, with comets as a keyword. Click on any of the following results, they all have different merits.
Sources (Information, Pictures, Videos)
Comet Hyukutake. N.d. Web. 8 Dec. 2015.
Miller, Ron. "Discovering Comets." Asteroids, Comets, and Meteors. Minneapolis, MN: Twenty-First Century, 2006. 35-55. Print.
NASA. NASA, n.d. Web. 03 Dec. 2015.
Observing Comet Siding Sprint at Mars. Dir. NASA Goddard. 2014. Youtube.
Types of a Comet. Digital image. N.p., n.d. Web. 10 Dec. 2015.