Philadelphia, Dec 25: People who gazed up into the sky and saw something rare. And, no, it wasn't a e Santa. He and his reindeers had already zoomed across the horizon. On Christmas Day, there was a full moon, the first since 1977. This full moon, the last one for 2015, is called a Full Cold Moon because it happens during the start of winter. Though "cold" is relative these days. Such a full moon won't happen again until Christmas 2034. On Friday night, the moon was 252,158 miles from Earth at a phase of 16.2% - which gave it the shape of a beautiful waning crescent. According to the lur cycle, in which the moon's phases are repeated on the same dates every 19 years, a Christmas Day full moon should also have occurred in 1996. But leap years can throw the dates out slightly and in 1996, the full moon was on Christmas Eve instead, meaning the last time it happened was in 1977.
John Keller from SA's Goddard Space Flight Center in the USA, said: "As we look at the moon on such an occasion, it's worth remembering that the moon is more than just a celestial neighbor.
"The geologic history of the moon and Earth are intimately tied together such that the Earth would be a dramatically different planet without the moon."
Friday night's full moon will be the last one of 2015 and will bring the curtain down on an amazing year of celestial events that included the supermoon lur eclipse in September and solar eclipse in March.