A blue moon is expected to rise Tuesday night, but what does that really even mean?
According to the Examiner, blue moons describe a situation when two full moons appear in the same lunar month.
But for those of you who follow along with the lunar cycles, you’ll know the blue moon we are expected to have on Tuesday night isn’t the second full moon in the month of August.
So then why all the hype? The blue moon that we are expected to have Tuesday night is actually the marking of the third full moon in a season.
According to the Weather Channel:
“When Tuesday’s full moon rises to its peak at 9:45 p.m. eastern time, it’ll be a “seasonal blue moon” — the third of four full moons in a season. A seasonal blue moon hasn’t happened in nearly three years, EarthSky reports.”
The Examiner continued on to say that while blue moons usually occur once a year, once every 19 years two blue moons occur in one year.
Yahoo reported that full moons occur every 29.5 days on average, when the moon is directly opposite the sun from the perspective of Earth.
“This causes its whole disk to be fully illuminated as a large, bright circle.
“Usually, when the moon is full, it passes either above or below Earth’s shadow, but sometimes, when it is perfectly aligned, it travels right through the shadow, causing a lunar eclipse, when its disk is dark.”
Ever heard the expression “once in a blue moon”? Well, the expression actually comes from the fact that blue moons don’t occur too often.
Here is another question people seem to be asking, will the moon actually be blue? According to the weather channel it isn’t actually blue.
After Tuesday’s blue moon, Yahoo reported that the next blue moon of this kind won’t occur again until 2015.