A newfound comet could put on a spectacular show in Earth's skies in early 2015.
The comet — officially cataloged as 2014 Q2, or Q2 for short — should be a fine object to view in small telescopes and binoculars during much of January. In dark skies free of significant light pollution, the comet may even be visible with the unaided eye.
Amateur astronomer Terry Lovejoy first discovered 2014 Q2 just before dawn on Aug. 17, 2014, from his roll-off roof observatory in Birkdale, Queensland, Australia. The newly discovered comet is the fifth one Lovejoy has found since 2007. He spotted it on CCD camera images he took using a Celestron C-8 telescope. [Take Space.com's Comet Quiz]
When Lovejoy first saw the comet, it appeared as a diffuse glow about 4,000 times dimmer than the faintest star visible to the unaided eye. At that point, the comet was located in the southern constellation Puppis and moving very slowly northwestward.
The comet is now performing far better than original forecasts had suggested. As of Dec. 26, Lovejoy was shining at magnitude 5.3. Observers using binoculars and small telescopes have described it as a circular patch of white light, roughly half the apparent width of the moon.
The size of the comet's coma (the atmosphere surrounding the comet's icy nucleus) currently measures about 229,000 miles (369,000 kilometers).
Long-exposure photographs have indicated a wispy, narrow appendage extending outward from the comet, as well as a strong greenish hue within the coma due to the presence of cyanogen and diatomic carbon. Both of these substances glow green when illuminated by sunlight.
The comet is due to make its closest approach to Earth on Jan. 7, coming as close as 43.6 million miles (70.2 million kilometers). If you assume that the comet continues to brighten at its current rate, Lovejoy should be at its brightest at that time. It could be as bright as magnitude 4.6, which would make it one of the brightest comets located high in a dark sky since the unexpected outburst of Comet Holmes in October 2007. [101 Amazing Skywatcher Photos from 2014]
That's a bit brighter than Eta Ursae Minoris, the faintest of the four stars in the bowl of the Little Dipper. So, will you be able to glimpse the comet without any optical aid? The answer is simple: If you can see all four stars in the Little Dipper's bowl, you should be able to see the comet. But you have to know exactly where to look.
Comet Lovejoy is moving along a south-to-north path, nearly perpendicular to the celestial equator, meaning that it will become increasingly better placed for northern observers with each passing night during the coming weeks.
Currently, a bright waxing moon will interfere with the ability to see Comet Lovejoy. The moon will turn full on Jan. 4, and it will light up the sky through the entire night. But on Jan. 7, the moon will rise about an hour after the end of astronomical twilight, meaning that there will be about an hour of dark sky to view the comet.
Each night thereafter, moonrise comes about an hour later than the previous night, meaning progressively longer intervals of darkness while the comet climbs higher and toward a better observing position for early-evening viewing.
Comet Lovejoy is now in the constellation Lepus, and during the first week of January, it will move rapidly to the northwest from Lepus into Eridanus, and then into the constellation Taurus by Jan. 9.
— Joe Rao, Space.com
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer's Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York. This is a condensed version of a report from Space.com. Read the full report. Follow Space.com on Twitter, Facebook and Google+.
Thanks to Amazing Sky's Alan Dyer and Thomas Pappalardo for sharing their comet pictures, and thanks to Sky & Telescope for sharing its finder map. Check out this viewing guide by S&T's Alan MacRobert, plus this PDF finder map for December viewing and this map for January viewing. For more of Amazing Sky, take a look at Dyer's website, blog, photo galleries, Flickr photostream, Vimeo channel and Facebook page.