May Flower Supermoon: When Is the Next Full Moon and What Does It Mean?

May's full moon—also known as the flower moon—is the fourth and final supermoon of the year and it will take place this week on Thursday, May 7.

According to The Farmer's Almanac, May's full moon takes its name from the bounty of flowering of plants visible at this time of year. It is a tradition that dates back to Native Americans naming the moons to keep track of the seasons.

May's moon can also be called the full corn planting moon, as it marks the period after the frost when the farmers start to seed the fields, and the full milk moon, as it marks the time in Europe when dairy farmers would move cows to summer pastures.

But this year's full moon is also a supermoon, meaning it appears marginally larger than the average full moon.

"'Supermoon' was defined, quite arbitrarily, by an astrologer—not an astronomer—Richard Nolle, as any full moon that occurs when the Moon is within 10 percent of its closest approach to Earth—called perigee—on a given orbit," Dr. Richard Tresch Fienberg of the American Astronomical Society told Newsweek.

"That last part of the definition, 'on a given orbit,' is critical, because the Moon's perigee—and apogee, i.e., farthest distance from Earth—changes from orbit to orbit due to gravitational perturbations by the Sun, Earth, and other solar system bodies."

This month's supermoon is the fourth and final of the year, and will be slightly less bright and not quite as close as the April and March supermoons. Though, as astronomers have pointed out, the difference in a supermoon and a full moon is so slight, it is not necessarily perceptible to the naked eye at the best of times.

"There won't be much variation really, and in fact the difference between a 'normal' full moon and a 'supermoon' goes unnoticed by most—it's only a few percent change in size, and corresponding luminosity," Ed Bloomer, an astronomer at Royal Observatory Greenwich, told Newsweek.

"The most important thing is really that it's going to be a nice full moon, so we'll see the entire Earth-facing side of the Moon illuminated, giving a great view of the surface."

According to NASA, the Moon will appear full for around three days from Tuesday evening to Friday morning.

The best time to watch is the night of May 6-7, when it will reach its fullest at 6:45 a.m. EDT Thursday morning. By this time, the Moon will have set on the east coast but remain visible to those on the west coast, where it will be 3:45 a.m. PDT. However, if it happens to be cloudy where you are, Fienberg's advice is to try again the following night.

Both Fienberg and Bloomer suggest picking up binoculars if you have a pair to hand and using them to gaze at the moon's craters and the darker lunar "maria," which comes from the Latin for seas. The moon's dark patches are so-named because astronomers once confused them for such.

"It's especially fun to look at the full Moon as it's rising or setting. Then you experience the 'moon illusion,' where the Moon looks bigger closer to the horizon than higher in the sky—where it's actually a little bit closer to the observer and should therefore appear bigger," said Fienberg.

"This is an eye-brain thing, not an astronomy thing, but that doesn't make it any less wondrous."

Bloomer's top tip is to make your surroundings as dark as possible.

"Switch off as many lights as you can nearby so you're not competing with other bright sources," he said. "Although the Moon looks bright, it's only relatively bright, and won't compete well with a mobile phone screen at eye height."

Full moon
A "super pink moon" rises on April 8, 2020 in Wellington, New Zealand. Hagen Hopkins/Getty Images

May's supermoon isn't the only astronomical event coming up this month. Fienberg says it is a great month for planet-watching with Venus visible in the west at dusk and blazing brighter than any star. On May 21, Venus will be joined a fainter Mercury, which will appear in the west-northwestern horizon.

Throughout May, Jupiter and Saturn will be visible from northern lattitudes around midnight, moving westwards as the month progresses.

According to NASA, Jupiter and Saturn can be oberved with Mars on the morning of Thursday, May 7, 2020 at twilight (4:58 a.m. EDT for the Washington, D.C. area). The planets will appear in the southeastern sky, with Jupiter shining brightest at around 28 degrees above the horizon. Saturn is due to appear approximately 5 degrees to the left of Jupiter and Mars 22 degrees above the horizon in the southeast.