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The Last Supermoon of 2014

Don't miss the supermoon of September 9—it's the last one of 2014! Supermoons aren't to be missed, as they appear bigger and brighter than regular moons. Though the name "supermoon" isn't an official scientific one, the principles behind this astronomical phenomenon certainly are.

Though many people might believe that planets and moons have perfectly circular orbits, they are all actually slightly elliptical, or oval-shaped. Therefore, when the Moon orbits the Earth, the distance between the Moon and the Earth varies between about 222,000 miles (at minimum, called the perigee) and 252,000 miles (at maximum, called the apogee). Supermoons occur when a full moon (or a new moon) rises when the Moon is at its perigree, or at its closest to the Earth. (This is why the scientific name for this phenomenon is the perigee full moon.) A full moon at perigee will look larger from Earth because it is physically closer.

Similarly, when the Moon rises at apogee, it will appear smaller and dimmer to us on Earth. Though these "micromoons" are not as popular as supermoons, they occur for the same scientific reasons that supermoons do.

Besides being a beautiful spectacle in the night sky, supermoons can also have an effect on Earth's tides. When the Moon is at perigee, the gravitational effect it has on the oceans is a bit stronger, causing a change in the tides.

Make sure you don't miss the September 9 supermoon by checking your local moonrise time here. Learn more about the Moon, Earth's only natural satellite, with these resources from Science NetLinks: the Lunar Cycle lesson; the Sky 4: The Moon lesson; and the Team Moon lesson.

image credit: clipart.com

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