Once in a blue moon

The last full moon of summer rose over Sundance on Wednesday evening. It not only marked the end of the season, but the last time a blue supermoon will grace the skies until the year 2037.

This two-for-one event includes a pair of lunar phenomena, the blue moon and the supermoon.

A blue moon is the uncommon occurrence of two full moons in a single calendar month. It gets its name from a 16th-century expression "the moon is blue", which meant something that was impossible.

However, after Krakatoa erupted in 1883, strange sunsets appeared around the world and the moon did indeed appear blue, whi...