The Harvest Moon as seen in September 2013 around NASA’s Goddard Space Flight Center in Greenbelt, Maryland. According to folklore, every full moon has a special name that says something about the season or month in which it appears. Photo courtesy of NASA/Goddard/Debbie McCallum

Why on Earth are there so many moon names?

The Earth has only one moon.

But there are many descriptions for that moon, and some of the most interesting are listed in the “Old Farmers’ Almanac.” For instance, early Native Americans referred to the full moon in June as the strawberry moon, because it was a signal to harvest the wild strawberries. They called the April moon the pink moon because of the flowers blooming, the July moon was the buck moon because antlers appeared on deer during that month, and September was the corn moon because of the harvest.

A supermoon rises behind the Washington Monument on June 23, 2013, in Washington. The moon was up to 13.5 percent larger and 30 percent brighter than a typical full moon. This is a result of the moon reaching its perigee — the closest that it gets to the Earth — during the course of its orbit. During perigee on June 23, 2013, the moon was about 221,824 miles away, as compared to the 252,581 miles away that it is at its apogee — farthest distance from the Earth. Photo courtesy of NASA/Bill Ingalls

Likewise, in the fall, the harvest moon appears very large and orange because the moon’s path and the Earth’s atmosphere can create the illusion. In autumn months, there are more dust particles in the atmosphere, which means light rays are scattered as they pass through clouds, scientists explain. Blue, green and purple light are dispersed, leaving the orange and yellow hues, thus, an orange-like color appears. And in the fall, the moon is lower in the sky and closer to the horizon, making it appear closer.

A blue moon really isn’t blue.

“When you hear someone say, ‘Once in a blue moon’, you know they are talking about something rare,” according to NASA. “A blue moon is not blue in color. In fact, a blue moon does not look any different than a regular, monthly full moon.”

Rather, a blue moon is special because it’s the “extra” moon in a season with four full moons, according to NASA. This usually only happens every two-and-a-half years. Since the 1940s, the term blue moon also has been used for the second full moon in a calendar month.

The last blue moon was March 31, 2018; the next one will be Oct. 31, 2020.

Although blue moons are pale gray and white like any other moon, there’s a record of a blue-colored moon in 1883 in Indonesia after a deadly volcano. More than 36,000 people died in a blast described as 10 times worse than the effect of the atomic bomb in Hiroshima. Dust from the eruption acted as a filter, causing sunsets and the moon to turn blue and green worldwide. Forest fires and dust storms can have the same effect.

The super blue blood moon during the early morning hours of Jan. 31, 2018, from the Johnson Space Center in Houston. The lunar event combined three rare phenomena: a blue moon, a supermoon and a total eclipse. Photo courtesy of NASA/Norah Moran

The first full moon of spring is called the egg moon or Easter moon and appears the week before Easter. And the last full moon of winter is called the Lenten moon. And there’s the full moon before yule and the moon after yule in December, as well as the black moon, which is the second new moon in a calendar month. New moon is the phase when the moon cannot be seen and only the dark side faces Earth.

Last year, there was much excitement about the supermoon, when the full moon approach is closest to the Earth and it appears larger than normal. In fact, it is larger — by only about 6 percent — and it is about 16 percent brighter. It’s about 223,600 miles from Earth at that time, as opposed to the micromoon, or minimoon, when it is farthest from Earth — about 251,000 miles away. Mark your calendar now: the next supermoon is Nov. 25, 2034.

And what was the rock group Pink Floyd describing in 1973 with its album, “Dark Side of the Moon”? The far side is sometimes called the dark side of the moon, meaning unseen rather than lacking light.

Only one side of the moon is visible from Earth because the moon rotates on its axis at the same rate that the moon orbits the Earth, so the dark side isn’t really dark at all. But it wasn’t until 1959 when the Soviet spacecraft Luna 3 transmitted grainy images of the area that we learned it was just like the part visible from Earth.