2013 could be a banner year for comets, with not one, not two, but three of them being visible to the naked eye. Two are already visible in the Southern Hemisphere, as seen in the video, and they’ll be coming up north in the next few weeks.
Comet PanSTARRS is currently shining at magnitude +4.2, equivalent to a faint star, but getting brighter. Here’s a graph of its progress:
The blue line shows the brightness of the comet, compared with predictions; it started out fainter than expected, but has started shooting up, so it’s still on track to match the brightest stars in the sky, if we’re lucky.
The best show for stargazers in the Northern Hemisphere should come just after Comet PanSTARRS swings around the Sun on March 10–probably on March 12, just after sunset, before the Moon starts to wash out the sky. If you can find a clear view of the western horizon that week, I encourage you to take a look. You can check out the guide at Universe Today for more details.
One naked-eye comet would be worth a headline by itself, but now we have the surprise newcomer, Comet Lemmon. It’s not quite as bright as Comet PanSTARRS, but it’s just barely visible to the naked eye and is likely to get almost as bright. There’s a good chance that Comet Lemmon with be visible in the Northern Hemisphere come April.
You’ll notice from the video that PanSTARRS is a traditional white comet, which Lemmon is bright green, more like Comet Holmes in 2007. The green color comes from a higher concentration of cyanogen and diatomic carbon gases in the comet’s ices.
I’ll post more about Comets PanSTARRS and Lemmon as they come closer, and, of course, we have Comet ISON to look forward to in the fall. Just remember, as David Levy say, “Comets are like cats; they have tails, and they do precisely what they want.”