Science Series: Harvest Supermoon

Science of the Harvest Supermoon

See it Tonight

Non-supermoon vs. Supermoon. Image: NASA Science

When we talk about a Supermoon, we’re not referring to Clark Kent’s secret identity. A “super” moon occurs when a full moon coincides with the Moon’s orbit around the Earth, which is closest in its elliptical orbit, known as perigee. This means the Moon’s appearance in the sky is 14% to 30% larger and brighter than that of a regular full moon, not a supermoon. Because the Moon is closer to the Earth, tides can be higher than usual. And, of course, there are the werewolves to consider.

The term “supermoon” was coined by astrologer Richard Nolle in 1979 as either a new or full Moon that occurs when the Moon is within 90% of its closest distance to Earth.

Supermoons may or may not be “Super Blue Moons,” having nothing to do with an election year or the song by Rodgers and Hart that was popularized by The Marcels. As I’ve explained in this article on blue moons, these occur when there are more than two full moons in the month.

But tonight is not a blue moon. Instead, it’s a…

Harvest Moon