Fireworks won't be the only thing lighting up the sky this New Year's Eve. It'll be shared with a special sort of full moon.
A blue moon.
The term refers to two full moons occurring in a single month, not the actual colour, according to Wikipedia. A new moon happens every 29.5 days, meaning that a year with 13 full moons only happens every 2 1/2 years.
The last blue moon happened in May 2007, but a New Year's Eve blue moon is even more rare, happening every 19 years.
This means the last New Year's Eve blue moon happened in 1990, and the next one will happen in 2028.
Not everyone on the globe will experience the New Year's Eve blue moon, though Sudburians will. People celebrating in the United States, Canada, Europe, South America and Africa will all see the second full moon of the month.
Party-goers in Australia and Asia, however, see the full moon on Jan. 1, meaning that January is their blue moon month.
People in Europe will also see a lunar eclipse, though the Americas will not.