If the skies are clear, revelers looking up at midnight will get an eyeful of the second full moon of the month—commonly called a blue moon. The last time a blue moon appeared on New Year’s Eve was in 1990, and it won’t happen again until 2028.

A blue moon isn’t actually blue—as commonly defined, the name reflects the relative rarity of two full moons in a month and is linked to the saying “once in a blue moon.”

The phrase blue moon refers to when a second full moon occurs within a calendar month. With the lunar cycle taking roughly 29.5 days, it generally happens every two to three years. The moon itself does not change colour.

A blue moon is scheduled for 7.13pm New Year’s Eve, but astronomers work in Greenwich Mean Time.

Because Australia’s time zone is ahead of England, the full moon will actually occur at 5.13am January 1, Brisbane time.

The fact that it doesn’t fall in the same month means it can no longer be considered a blue moon.

Mark Rigby, curator of the Brisbane Planetarium, said the term full moon referred to the specific point when the moon was on the opposite side of the Earth to the sun.

“If you were in London you could celebrate on New Year’s Eve under a blue moon, but not at our latitude,” Mr Rigby said.

“It is a specific moment in time when you have the sun, Earth and moon all in a straight line.”

Australians devastated at losing this astronomical boost to their celebrations can take solace in the fact we will be compensated with an even rarer event: a month with no full moon.

After New Year’s Day’s full moon, Australia will experience a blue moon on January 30, followed by no full moon at all in February. We will then have a second blue moon in March, coming on March 30 after a first full moon on March 1.

The last blue moon occurred in Australia in 2007, but the last time February had no full moon was 1991. It is not due to occur again until 2018.

  Copyright secured by Digiprove © 2009