There are now four morning comets visible in 10×50 or larger binoculars from a dark sky site: Lovejoy, ISON, Encke and C/2012X1. The last is the faintest and Encke, while bright at magnitude 7-7.5, is now getting so low, it’s not easy to find for most observers. That leaves us with two reasonably bright targets at comfortable elevations.
A word to the wise – don’t wait too long to see ISON and Lovejoy. The glare of the moon returns to the sky around the 15th and will make both more challenging to find. At the moment Comet Lovejoy is considerably brighter and easier to see then ISON with a magnitude of around 6 versus 8. I even saw it faintly with the naked eye two mornings ago just a finger to the east of the Beehive Cluster.
So why is Lovejoy so much brighter than ISON the Great right now? Well, it’s much closer to Earth – 42 million miles versus 93 million for ISON. In astronomy, proximity counts. The closer something is, the brighter it looks. There is no better example of this than staring up at the sky on a clear night. Many of the brightest stars achieve that status because they’re closer than the fainter but intrinsically brighter ones.
ISON will hopefully far outshine Lovejoy as we move into late November when the comet get a heavy-duty broiling from the sun. It will pass nearest Earth on Dec. 27 at a distance of 40 million miles. By then Lovejoy will have receded to ISON’s current distance of 93 million miles. Interesting that they they’re moving counter to one another this way.
While Lovejoy will continue to brighten and could reach 5th magnitude, ISON could become MUCH brighter. The latest estimates have it at the same brightness as Venus (-4 magnitude) for a few hours when it’s closest to the sun on Nov. 28.
The best time to view both comets is right before the start of morning twilight or about 1 3/4 – 2 hours before sunrise. You can click on the charts to get higher-resolution versions of them to print out for use outdoors. Good luck on your comet quest!