The March Worm Moon — The First Supermoon of 2021?

~3 min

You might hear that the first supermoon of 2021 is coming in March, but is it really so? In this article, we’ll try to figure it out. We’ll also provide you with the exact dates of the supermoons of 2021 and explain how and when to spot them. Let’s begin!

Is the March Full Moon a supermoon?

The first Full Moon after the March equinox falls on March 28 at 2:48 p.m. EDT (18:48 GMT). Can we call it a supermoon? The answer depends on what you consider a supermoon. The thing is, there is no official astronomical definition of this phenomenon. In our “Full Snow Moon 2020: Is It a Supermoon?” article, we explained how this term was made up and what it originally meant. Initially, it was coined by astrologer Richard Nolle in 1979. He defined a supermoon as "a New or Full Moon at or near (within 90% of) its closest approach to Earth in a given orbit". Thus, if we use the original definition given by Richard Nolle, we can’t call the March Full Moon a supermoon.

However, the March Full Moon will be closer to the Earth than a usual Full Moon. The distance between the Earth and our natural satellite in full phase will be 362,170 km (or 225,042 miles), which will be the 4th closest Full Moon of 2021.

What happens during a Supermoon?

The media advertise a supermoon as the largest and brightest Moon of the year, but in reality, it’s not dramatically bigger than a usual Full Moon.

Let’s face the facts. At its largest angular size, the apparent diameter of a supermoon is 14.1% larger than the smallest Full Moon (a Micro Full Moon) and only 6.9% larger than a regular one. This is so insignificant that you won’t even notice the difference with a naked eye. There is, however, a so-called Moon illusion that might make the Moon look bigger than normal, but this illusion has nothing to do with the supermoon phenomenon.

Take photos and then compare Full Moons of different months to see if there will be any significant changes in the Moon’s appearance. The essential planner for outdoor photographers Ephemeris will help you to take amazing pictures — it contains all necessary information for setting a perfect shot and helps to visualize your future photo.

What is truly remarkable is that a supermoon may bring the largest tides of the year because a closer Moon causes a stronger gravitational pull and creates more variation between the tides. But it’s unlikely to bring massive earthquakes, flooding, or volcanic eruptions.

How many supermoons will be in 2021?

Most of the sources agree that there will be at least two supermoons this year: on April 27 and May 26. Some claim that the June Full Moon will be a supermoon as well, but it wasn’t included in the 21st Century supermoon list made by the author of the “supermoon” term Richard Nolle.

Why is the March Full Moon called a Worm Moon?

Regardless of being a supermoon or not, a Full Moon is still an exciting event for astronomers. Each Full Moon has its own name that comes from different places, including Native American, Colonial American, and European sources. The March Moon goes by the name Worm Moon — one of the theories says that it refers to the earthworms that appear as the soil warms in spring. This attracts robins and other birds, which symbolize the beginning of spring in the Northern Hemisphere.

Hope we answered your question and gave you an item on your stargazing to-do list. Wishing you clear skies and happy observations!