Full Worm Supermoon to Appear in Sky Tonight: How and When to Watch March Full Moon

The last full moon of winter will appear in the sky on Monday night. The full moon in March is traditionally referred to as the Worm Moon. This full moon is also described as a supermoon—a popular term for when our satellite is close to its perigee, its minimum distance from Earth.

While supermoons are slightly larger in the sky than the average full moon, the differences are barely noticeable to the naked eye.

"Most people—including experienced stargazers—cannot tell the difference between a supermoon and any other full moon, because full moons are seen only once every month, and you cannot compare one to another directly," Rick Fienberg, a spokesperson for the American Astronomical Society, previously told Newsweek.

In fact, the term "supermoon" is not a scientific one, but was instead introduced by an astrologer (not astronomer) called Richard Nolle. He defined a supermoon as any full moon that occurs when our natural satellite is within 10 percent of its perigee on a given orbit. However, there are no official rules for what constitutes a supermoon.

Technically, the full moon on March 9 takes place at specific moment, when the Earth is positioned directly between the moon and the sun. At this point our natural satellite appears like a perfect circle and is fully illuminated by our star. On March 9, this moment will occur at 1:47 p.m. ET.

For most observers, the moon will look full for around a day either side of the this time, rising at sunset and setting at dawn. According to Luca Masi, an astronomer from the Virtual Telescope Project, the best time to view the full moon is during the twilight hours of dawn and dusk.

The last supermoon of 2019, known as the "super worm equinox moon," is seen past tree branches over Karak in Malaysia's Pahang state on March 22, 2019. MOHD RASFAN/AFP via Getty Images

If you would like to check when the moon will rise and set in your location, please view this moonrise and moonset calculator provided by The Old Farmer's Almanac.

"During the twilight, the residual solar light scattered all around by our atmosphere allows us to admire the scenery, while the full moon rises or falls on the horizon," Masi previously told Newsweek. "At night, the full moon is very bright, almost dazzling, compared to the darkness of the landscape.

"At its rise, the moon appears behind monuments and elements of the landscape, generating the feeling that its disk is larger than usual, but this is just an optical illusion, due to the presence of those terrestrial elements in the line of sight, giving grounds for comparison."

The traditional name Worm Moon is thought to have been given because earthworms tend to emerge at this time of year in the Northern Hemisphere, according to timeanddate.com. This moon is the last full moon before the spring equinox, which occurs on Thursday March 19 at 11:50 p.m. ET, marking the end of astronomical winter.

It is also the second of four consecutive supermoons in 2020. The next full moon will appear on April 8.