It is any stargazer and photographer’s dream: the first of four supermoons this year lit up the sky around the world tonight. A supermoon, which is more a popular term than a scientific one, is used to describe when the moon is at its closest to the Earth, at the same time that it’s full. The phenomenon usually occurs only three or four times a year. Because the moon inches a little closer than usual, it appears to be larger and brighter. Tonight’s supermoon was especially rare as it was also a Blue Moon. This rare instance occurs when there are two full moons within a single calendar month or…