We are about to have our closest full moon since the World War II era, and astronomers are excited.
It has been an astonishing 80 years since the Full Moon has gotten this close to the Earth, and Supermoon 2016 promises to be quite a sight. The Supermoon is an event that happens pretty often, referring to when the moon is at its closest point to Earth in its elliptical orbit, but this event is pretty rare.
It was back on Jan. 26, 1948 when we last had a Full Moon as close to the Earth as we’re going to get on Nov. 14. Then, the moon will reach its perigee – that is, its closest point to the Earth – just two hours and 22 minutes before turning Full. The next time the Full Moon will be this close will be on Nov. 25, 2034.
The moon travels in an elliptical orbit that reaches 405,400 km from Earth at its farthest and 362,600 km at its nearest, an orbit that takes 27.55 days. A Supermoon is when a Full Moon happens within 24 hours of perigee. The opposite is the Minimoon, which is when the Full Moon happens within 24 hours of apogee.
“The term supermoon has entered popular consciousness in recent years. Originally a term from modern astrology for a new or full moon that occurs when the moon is within 90% of its closest approach to Earth in a given orbit, supermoon now refers more broadly to a full moon that is closer to Earth than average. But why is the moon closer to Earth at some times but not others?” a NASA statement reads. “Since the moon’s orbit is elliptical, one side (perigee) is about 30,000 miles (50,000 km) closer to Earth than the other (apogee). The word syzygy, in addition to being useful in word games, is the scientific name for when the Earth, sun, and moon line up as the moon orbits Earth. When perigee-syzygy of the Earth-moon-sun system occurs and the moon is on the opposite side of the Earth from the sun, we get a perigee moon or more commonly, a supermoon!”