For the first time in more than 30 years, residents of the Americas will get to witness a supermoon lunar eclipse, according to CBS News. A supermoon is when a full moon occurs at the same time as its perigree, the point in orbit when it's closest to Earth. This makes it seem larger and brighter than it actually is, and when it coincides with a lunar eclipse, the moon enters the Earth's shadow.
Both supermoons and lunar eclipses don't happen often, making the event rarity, according to The Christian Science Monitor.
"That's rare because it's something an entire generation may not have seen," said Noah Petro, deputy project scientist at NASA's Goddard Space Flight Center. "Because the orbit of the moon is not a perfect circle, the moon is sometimes closer to the Earth than at other times during its orbit. When the moon is farthest away it's known as apogee, and when it's closest it's known as perigee."
Due to its perigee, the moon will look approximately 14 percent larger and 30 percent brighter than an apogee full moon, according to The Hindu. These characteristics are what started the term "supermoon."
The event will take place on Sept. 27 and marks the first time a supermoon lunar eclipse has occurred since 1982. They have only occurred five times since 1990 and after this month, the next occurrence will be in 2033.
For more on the supermoon, click here.
