Photographers around the world ventured out Wednesday evening and overnight to document a rare phenomenon - the supermoon, which also happens to be a “Blue Moon." According to NASA, the next time two full moons will appear in the same month along with a supermoon will be in March 2037.
The moon's orbit around Earth is elliptical, and its distance from the Earth varies between 356,000 kilometers to 406,000 kilometers, a change of about 10% in its distance from Earth over the course of the month. Therefore, when the full moon coincides with its closest approach to the Earth, a supermoon occurs.
The occurrence of two full moons in the same month is relatively rare, happening about once every three years or so, with the second full moon known as a Blue Moon. This is not due to its color, however, but because of various traditions stemming from the anomaly of having a second full moon in the same month.
The name is linked to a concept taken from American folklore, saying that a rare event takes place "once in a blue moon."