Saturday Night: Full Moon Coincides with Perigee

Tonight's full moon is rather special. First, the moon will be full, which is always an amazing and beautiful sight. Second, the moon will be at perigee. Perigee is the point in the the moon's monthly orbital period where it is closest to the Earth. Conversely, apogee is the point in the moon's monthly orbital period where it is farthest from Earth. This month's perigee will be the closest approach towards the Earth the moon has made in 18 years. This fact, along with the moon illusion, means that if you catch the moon near moonrise or moonset, you are in for a spectacular view, and I strongly encourage everyone go outside and gaze at the moon tonight, even if only for a quick glimpse. Here is a calculator to find the moonrise and/or moonset times at your location.


Source SPACE.com: All about our solar system, outer space and exploration

However, I cannot say I am thrilled about the media dubbing tonight's event a "supermoon". While this combination of events is relatively rare, calling it a "supermoon" helps inflame rumors and panic that this full moon will generate natural disasters, such as huge earthquakes or volcanic eruptions. It will result in a larger range in the tides (i.e., high tide will be higher than normal and low tide will be lower than normal) over the next two or three days, called a perigean spring tide, which could possibly cause minor coastal flooding.

However, as an astronomer, I am thrilled anytime the general public is interested in astronomical phenomena. In the modern world, I think we sometimes take for granted the incredible celestial bodies which light up our night sky. Personally, I am greatly anticipating observing the full moon with my telescope tonight.