The green comet will zip out of the sky soon. You can still see it.

Punxsutawney Phil emerged from his burrow and saw his shadow, banishing the green comet from the night sky for 50,000 years.

Okay, okay, that's not what happened. But as the groundhog poked his head out on Feb. 2, a comet dragging a millions-of-miles-long tail through space was in the midst of its closest pass by Earth since...