A “Once in a Civilization” comet will be paying us a visit next New Year’s Eve. From Scientific American:
Why is this comet expected to be so unique? Two reasons:
Astronomers predict that the comet will pass just 1.16 million miles from the Sun as it swings around its perihelion, or closest approach. (This may seem like a lot, but remember—the Sun is big. If we were to scale the Sun down to the size of Earth, the comet would pass well within the orbits of dozens of satellites.) The close approach will melt enormous amounts of the comet’s ice, releasing dust and gas and forming what should be a magnificent tail.
After it loops around the Sun and forms this tail, the comet should then pass relatively close to Earth—not near enough to cause any worry, but close enough to put on a great show. Viewers in the Northern Hemisphere will get the best view as the comet blooms in the weeks approaching Christmas 2013. The comet could grow as bright as the full moon.
Comets can be somewhat unpredictable (remember the last appearance of Comet Halley?) but this one looks like it probably won’t disappoint. The “once in a civilization” moniker makes me a little squeamish, though people with a much better understanding of orbital mechanics than I have insist there’s no way this thing will hit us.
But being so big, and so close, passing right over Earth next New Year’s Eve will be quite a show. Brighter than the full moon and maybe even visible in daylight.
If you’d like to make yourself feel a little better about probabilities and all, here’s NASA’s orbit visualizer.