SEATTLE — Cross your fingers for some clear nights over the rest of the year, as three straight supermoons will light up the night sky. Don’t miss the first one on Oct. 6.
A supermoon is a full moon that appears larger and brighter than normal because it is at a point known as perigee. Because the moon’s orbit around the Earth is elliptical, the perigee is the moon’s closest approach to our planet.
“Supermoon” isn’t an official astronomical term, but typically it’s used to describe a full Moon that comes within at least 90 percent of perigee,” NASA wrote on its website. “Supermoons only happen three to four times a year, and always appear consecutively.”
PHOTOS | Supermoons shining bright
A supermoon is defined as when the moon is closer than 360,000 kilometers—about 223,694 miles—from the Earth.
On the evening of Oct. 6, the “Harvest Moon” will rise above the horizon. It is the full moon closest to the autumnal equinox and the start of fall.
“The name dates from the time before electricity, when farmers depended on the Moon’s light to harvest their crops late into the night,” according to NASA Space Place. “The Moon’s light was particularly important during fall, when harvests are the largest.”
The next full moon, the “Beaver Moon,” will fall on Nov. 5.
The Beaver Moon is the closest the moon will be to Earth all year.
“The Maine Farmer’s Almanac first published Indian names for the full Moons in the 1930s,” according to NASA. “According to this almanac, the Native American tribes of what is now the northern and eastern United States named this the Beaver Moon.”
“The Beaver Moon is the time of year when the beaver is preparing to build their dams before the ground freezes,” the National Park Service wrote on its website. “It is also the time of year the first snow falls in northern parts of the US and Canada.”
The last of the three supermoons is named the “Cold Moon.” This full moon will light up the night on Dec. 4.
“December’s full moon, the last of the year, is called the Full Cold Moon because it occurs during the beginning of winter,” NASA wrote. “
“This name underscores the harsh conditions of the winter season, with long nights and bitter cold prevailing,” Nebraskaland Magazine wrote on its website. “It’s a time of introspection, huddling close for warmth, and finding solace in the quiet stillness of the winter landscape.”
These three supermoons should wow amateur stargazers and professional astronomers alike.
“At perigee, the Moon can be as much as 14% closer to the Earth than at apogee,” NASA wrote on its website. “Something 14% closer to you appears 14% larger across and 30% larger in area, so a full Moon at perigee will reflect 30% more sunlight onto the Earth (in the form of moonlight) than a full Moon at apogee.
When the moon is closer to the Earth, the gravitational interactions can affect tides.
“The greatest difference between high and low tide is around Full Moon and New Moon, known as spring tides or king tides,” the website TimeAndDate.com wrote. “During these Moon phases, the gravitational forces of the Moon and the Sun combine to pull the ocean’s water in the same direction.”
Be sure to check local tide levels if you plan to be near the shore.
If you can’t catch the full moon on the exact day, don’t worry. The days before and after a full moon will still appear very large and bright.