In the sky: the Wolf Moon

Credit: Gregory H. Revera

Credit: Gregory H. Revera

Okay, you probably don’t need a stargazing guide to find the Moon. If it’s up, it’s pretty easy to spot, even in the daytime. Tonight, it’s even easier, since it’s a full Moon, specifically, the Wolf Moon, the traditional name of the first full Moon of winter. It also happens to be the 13th full Moon of 2012, since we had a Blue Moon back in August.

But the interesting thing about observing the Moon is that, unlike everything else in the sky, it’s easy to spot features on it’s surface with the naked eye, and you can see a lot more with binoculars or a telescope.

Major features on the Moon. Credit: Cmglee (Wikipedia).

Major features on the Moon. Credit: Cmglee (Wikipedia).

The largest features on the Moon are the maria, or “seas”. These are the dark splotches that make up the “Man in the Moon’s” face. Early astronomers thought they looked like seas and gave them names like “Sea of Tranquility”, “Sea of Rain”, and “Ocean of Storms”. We now know that they are ancient lava fields from when the young Moon was still hot enough to have volcanoes. On smaller scales, there are many similar features called “lakes”, “bays”, and “marshes”.

The other obvious features on the Moon are craters. The whole Moon is covered with craters down to the microscopic level, but a handful of them are easy to see from Earth and have been given names. The most famous Lunar crater is probably Tycho, the location of the monolith in 2001: A Space Odyssey. Tycho appears as a bright spot in the Moon’s southern hemisphere.

With a telescope, you can see a lot more features on the Moon, like mountains, ridges, and valleys. Many of those mountains are as tall as large mountains on Earth, like the Alps. It’s well worth a look; even though it’s smaller than Earth, the Moon is a big world with a geography all its own.

One more thing about the Blue Moon: today, it’s considered to be the second full Moon in a month that has two, which was the full Moon of August 31 this year. However, it was traditionally the third full Moon in a season that has four. This was done so that the names of the full Moons would not be thrown off. The first full Moon of summer is called the Hay Moon, the second is the Corn Moon, and the last is the Harvest Moon. This year, there was an extra full Moon on August 2–the Blue Moon.

[Update: I later learned that this method of naming full Moons around the seasons is very outdated. The modern custom is to name the full Moons for the month they are in, making the full Moon of January 26 the Wolf Moon. There are also many alternative names for each full Moon, some of which are more popular than the ones I used here, like this list from National Geographic.]

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About Alex R. Howe

I'm a full-time astrophysicist and a part-time science fiction writer.
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