Stunning Supermoon Lunar Eclipse is Coming

This month's highly anticipated "supermoon eclipse" may be a magical treat for skywatchers, but there's nothing supernatural about the event.

On Sept. 27, skywatchers throughout North and South America, Europe, Africa, western Asia and the eastern Pacific Ocean region will witness a total eclipse that happens to occur when the moon looks abnormally large and bright in Earth's sky. It will be the first supermoon eclipse since 1982, and the last until 2033.

NEWS: Beyond Sunday's 'Supermoon': Lunar Perigee Science

This rare celestial phenomenon has its roots in the moon's elliptical orbit around Earth. [Supermoon Lunar Eclipse: Complete Blood Moon Coverage]

"When the moon is farthest away, it's known as apogee, and when it's closest, it's known as perigee," Noah Petro, deputy project scientist for the Lunar Reconnaissance Orbiter at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. "On Sept. 27, we're going to have a perigee full moon - the closest full moon of the year."

The moon is about 31,000 miles (50,000 kilometers) closer to Earth at perigee than it is at apogee. As a result, perigee full moons, also known as supermoons, appear about 14 percent bigger and 30 percent brighter in the sky than do apogee full moons (which are also called minimoons).

Lunar Phases: The Changing Face of the Moon

"There's no physical difference in the moon," Petro said. "It just appears slightly bigger in the sky. It's not dramatic, but it does look larger."

"Normal" total lunar eclipses - which occur when the Earth, moon and sun align, and the moon passes completely into Earth's shadow - aren't terribly uncommon: On average, a skywatcher in a given location on Earth can expect to see one of these events every 2.5 years or so.

But it is uncommon for a total lunar eclipse to coincide with a supermoon. There have been just five such events since 1900 (in 1910, 1928, 1946, 1964 and 1982), NASA officials have said.

Rarity does not imply anything inexplicable, however.

Spectacular Supermoon Seen Around the World: Photos

"It's just planetary dynamics. The orbit of the moon around Earth is inclined to the axis of Earth, and the orbital plane of all these things just falls into place every once in a while," Petro said. "When the rhythms line up, you might get three to four eclipses in a row, or a supermoon and an eclipse happening."

The supermoon will begin to dim slightly at 8:11 p.m. EDT on Sept. 27 (0011 GMT on Sept. 28), NASA officials said. The total eclipse will start at 10:11 p.m. EDT (0211 GMT), and it will last 72 minutes.

More from SPACE.com:

How Lunar Eclipses Work (Infographic)

Amazing Supermoon Photos: Biggest Full Moon of 2014 How the 'Supermoon' Looks (Infographic)

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Astrophotographer Maxwell Palau captured this view of a total lunar eclipse from San Diego, California, on Oct. 8, 2014.

On July 12, the moon may have seemed slightly brighter to the casual observer. As part of a lucky coincidence between a full moon occurring at around the same time the moon is at perigee (i.e. the closest period of its orbit around Earth), the moon can appear brighter and larger than normal full moons. But the change isn't very dramatic and the event happens more often than you may think. In fact, this "supermoon" is the first of

three

supermoons that are scheduled over the next three consecutive months -- the next will be on Aug. 10 and Sept. 9. Though it is more of an astronomical curiosity, the supermoon event does attract its fair share of sky-watchers, so enjoy this small selection of photos from around the globe as people looked up to celebrate our planet's extra-bright satellite.

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In this shot, beach goers paddle in the Pacific Ocean at Venice Beach, Calif.

The supermoon rises over observatories atop the Bulgarian mountain peak of Rozhen on Saturday, July 12.

The full moon rises in the sky over the Orbital Sciences Corporation Antares rocket, with the Cygnus spacecraft onboard, July 12, 2014, launch Pad-0A, NASA's Wallops Flight Facility in Virginia. The rocket launched successfully on Sunday.

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A closeup of the full moon on July 12 over Athens, Greece.

The supermoon rises in the sky over Lower Manhattan in New York, July 12, 2014.

An airplane flies through a full moon referred to as a "supermoon" as it rises in the sky over Lower Manhattan in New York, July 12, 2014.

The supermoon shares the sky with fireworks during a display in Chester, New York.

A couple enjoys the supermoon on a beach in Xiamen city, southeast Chinas Fujian province on July 12.