Another rare celestial event will be occurring tonight, and you should definitely take time out of your Friday night to look up at night sky and appreciate it. On May 18, a full moon will brighten up the weekend sky. Dubbed the full Flower Moon the celestial event has an even more special definition, a "Blue moon".
You have probably heard of or have even used the phrase, "once in a blue moon." The neutral phrase iterates something that rarely occurs over a period of time. Dating back to 1528, the phrase itself evolved to what it means today, with it originally meaning something that was absurd similar to the phrase, "when pigs fly".
Just like the phrase, for the average person, the celestial term can be a bit confusing as the definition of Blue Moon has two definitions. Today we are briefly going to explore these terms and help you get acquainted with the phrase so that you can fully appreciate tonight's rare Blue Moon.
Defining a Blue Moon
There are two definitions of the Blue Moon. Unfortunately, neither of them have anything to do with the moon turning blue. Now full moons themselves occur every month. In fact, some of these same full moons are given names based on what is happening during that season or time of the month.
A Flower Moon may indicate the time of year when flowers come into bloom or the "Strawberry Moon" gets its name in June because that is when Strawberries are harvested. Yet, the term Blue moon gets a little bit weird as you can have a Full flower moon and a Blue Moon. Are you lost yet? Let us explain.
The phases of the moon are not completely perfect. In fact, the moon phases take approximately 29.5 days to complete. So, in short, this means that once every two to three years, there is a 13th full moon. Due to the fact that this moon is so unique and a rare occurrence, people tend to associate this moon with the phrase Blue Moon. However, this is still not absolutely correct.
Tis the Season
Off of this definition, in 2018 we had two blue moons, one on January 31 and a second one on March 31. Each of these moons was the second of two full moons to fall within a single calendar month. However, the Blue Moon of May 18, 2019, will be a seasonal Blue Moon, meaning the third of four full moons in one season. This brings us to our second definition of a Blue Moon.
A Blue moon is the third full moon in an astronomical season that contains four full moons. The ending of astronomical seasons falls at the end of the Spring and Autumn equinoxes and during the Summer and Winter solstices. 2019's Spring astronomical season contains four full moons, with May's full flower moon being the third; this is the Blue Moon that you will get to see this year.
Seeing the Blue Moon
You do not need any special instruments to see tonight's Blue Moon, just a clear night sky to enjoy all of its glory. Other astronomical bodies will be accompanying the moon tonight including Jupiter, Saturn, and Venus.