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Lovejoy Comet from the
International Space Station (photo credit: NASA, Dan Burbank)
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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 shareitscience@gmail.com
Read more:
- 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
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