Lovejoy Comet from the International Space Station (photo credit: NASA, Dan Burbank)
Before we get too far ahead of ourselves, let's put on the brakes and understand what it is we are actually seeing when we observe a comet. Comets are chunks of rock and ice leftover from when the stars and planets formed billions of years ago. These chunks usually hang out in the Oort cloud which is an icy shell of debris in solar orbit far outside of our solar system. The gravitational pull of the sun is not as strong at this distance, so on occasion these icy chunks are jarred loose of their orbit and make their way into our solar system. While they are in our solar system they settle into orbits that are not as predictable as the planets. As the comets get closer to the sun the ice begins to melt and this water vapor becomes the characteristic tail of the comet. The tail is the dirty melted water in its gaseous form.
Comet Lovejoy is named after its discoverer, Australian amateur astronomer Terry Lovejoy. Terry Lovejoy has discovered 5 comets to date. Lovejoy spotted this one back in August, 2014. This comet is what we call a long-period comet. This has not been its first trip near Earth, but with an orbital period of approximately 11,500 years you most likely missed it last time! It is thought that Comet Lovejoy won't be passing through again for about 8,000 years, so if you'd like to to see it, this is your chance.
Like many comets, Lovejoy has a bright green color. This coloration is due to molecules of diatomic carbon in its head that fluoresce in the ultra-violet light of the sun. The dust in the head of the comet also reflects sunlight, hence the bright streak we observe. There are many tools to help you orient yourself to the night sky in order to catch a glimpse of this comet. You can spot it with binoculars, or if you are in an area with no light pollution, you probably will be able to see it with the naked eye. The comet is currently just below the constellation Orion, which is usually pretty easy to spot. For best viewing you probably want to head outside around 9-10:00 PM. You can use this guide from Sky and Telescope to help you find it, or some of the tools I suggested in my post about viewing the Geminid meteor shower. So get out your trusty star wheel, fire up your Google Sky Map app, or use Stellarium on your computer to help you locate the constellation Orion, and then Comet Lovejoy.
I'm looking forward to trying to spot this comet in the next few evenings. I would love to hear your success stories from comet-hunting! Please leave me a comment below or e-mail me at firstname.lastname@example.org
- Universe Today: "Australian Amateur Terry Lovejoy Discovers New Comet"
- Sky and Telescope: "How to see Comet Lovejoy"
- Universe Today: "Finding Lovejoy: How to Follow the Path of Comet 2014 Q2 Through January"
Comet Activities and Resources:
- Lovejoy Comet Finder
- NASA Kids: Comets
- NASA: Make a comet model and eat it!
- From the Internet to Outer Space- Use Google Sky to observe features of the night sky
- NeoK12 Videos, Lessons and Games for K-12 about Comets