There's a blue moon tonight, something that's fairly rare, happening once every 2 1/2 years. That it occurs on New Year's Eve is even rarer, happening only once in 19 years. But wait! It gets better... there's also a partial lunar eclipse happening tonight, something that is particularly rare: in the next 1000 years, Blue Moons on New Year's Eve will be eclipsed only 11 times... once every 91 years. Cool, huh.