Look up to the sky Wednesday night to see this!

Everyone has heard the expression “once in a blue moon”, meaning a rare occurrence. Luckily, this unique celestial event, taking place once every two to three years, is right around the corner.

August has been quite the month for stargazers — including the sights of two supermoons, the popular Perseid meteor shower, and the grand finale, a blue moon.

When is the blue moon?

The blue moon will take place Wednesday, Aug. 30, according to Old Farmer’s Almanac. It will reach its peak at 9:36 p.m. It will also appear full the day prior to and following its peak.

This blue moon is also a supermoon, which only occurs four times a year. Not to mention, it’s the closest one to Earth.

What is a blue moon?

A blue moon is the second full moon to occur in a calendar month. Typically, full moons only happen once a month as they take place every 29.5 days on average, according to BBC Sky at Night Magazine. However, it is possible for two to fall during the same month as months are normally 30 to 31 days long.

 

Blue moons typically take place every two to three years, with the last one visible on Aug. 22, 2021. The next blue moon won’t occur until May 31, 2026. The modern understanding of a blue moon, also referred to as a monthly blue moon, is the second full moon of the month and is astronomically inaccurate.

A “seasonal blue moon”, the older definition, is specific to the astronomical season. An astronomical season occurs between a solstice and equinox, where three full moons are often seen throughout each quarter.

What is a supermoon?

 

 

A supermoon occurs when a full moon’s orbit is closest to the Earth, according to NASA. Because the moon travels the Earth in an ellipse, an oval-like shape, it moves closer and farther from the planet as it travels.

This year, the four supermoons are happening consecutively, which is a rare sight. The first took place on July 3 and the last will occur on Sept. 29.

The blue moon at the end of August will be the closest and brightest supermoon of the year, only 222,043 miles from Earth.