Tuesday, December 15, 2015

Catch Comet Catalina Before It’s Gone Forever

Comet Catalina

http://www.slate.com/blogs/bad_astronomy/2015/12/15/comet_catalina_is_your_christmas_star_for_2015.html?ref=yfp

If you get up early enough over the next few weeks—a couple of hours before sunrise should do it—and look east, you’ll see the brilliant beacon of the planet Venus. Fairly close to it in the sky, but not so obvious is a visitor to these parts; one that is just passing through. Literally.
The visitor is the comet C/2013 US10 (Catalina); most people are just calling it Comet Catalina (the official name has a bit more complicated nomenclature). There are a couple of very cool things about this comet you should know about, but before I get to that part let me tell you how to see it.
Although it’s bright as comets go, for now you’ll probably need binoculars to observe it unless you have pretty dark skies. It’s about magnitude 5 or 6 right now, which means it’s technically visible to the unaided eye, but it’ll be tough. Any optical aid you have like binocs or a good ‘scope would help.
Its orbit is tilted rather severely to the Earth’s; it has an inclination of 149° (or, if it helps, about 30° from Earth’s but moving around the Sun in more or less the opposite sense from Earth). In the sky it’s moving in a northerly direction, so folks north of the equator will see it higher in the morning every day. It will be closest to Earth on Jan. 17, when it’ll be roughly 100,000,000 kilometers away (which is close as comets go, but still a long way). After that it’ll pull away and start to dim, so seeing it will be harder.star map