June Strawberry Full Moon Will Feature a Lunar Eclipse: Everything You Need to Know

This Friday, a full "strawberry" moon will appear in the sky, as some parts of the world will be treated to what is known as a "penumbral lunar eclipse."

Lunar eclipses—of which there are three main kinds (total, partial and penumbral)—only occur when the moon is full. During the full moon lunar phase, the Earth is located directly between the sun and our natural satellite in space.

Penumbral eclipses are far more subtle than either total or partial lunar eclipses. The former occurs when the more diffuse, outer part of Earth's shadow —known as the penumbra—falls on the face of the moon.

When this happens, the moon—or parts of it—may appear to be slightly darker than usual. However, this difference in brightness is often difficult to observe.

"A penumbral lunar eclipse happens when our moon is 'kissed' only marginally by the most external regions of the structure of the Earth's shadow," astronomer Gianluca Masi, from the Virtual Telescope Project, told Newsweek.

Penumbral eclipses come in two forms themselves. They can be total, meaning that the whole of the moon is covered by the Earth's penumbra. Or they can be partial, where the penumbra only covers some sections of the moon. Partial penumbral eclipses, like Friday's, are harder to observe than total penumbral eclipses, but are far more common.

The eclipse on Friday begins at 1:45 p.m. ET, with maximum eclipse occurring at 3:26 p.m. ET, when 59 percent of the moon will be covered by the Earth's penumbral shadow. At most you might be able to see a slight shading in the southern portion of the moon. In total, the event is expected to last for nearly three hours and 20 minutes.

This eclipse is visible from Africa, much of Europe, most of Asia, Australia, a sliver of South America, Antarctica and the Pacific, Atlantic and Indian oceans—meaning North America will miss out. However, if you would like to watch it from North America, the Virtual Telescope Project will be providing a live stream of the event from Rome, Italy beginning at 3 p.m. ET on June 5.

During the eclipse, the moon will not be in the sky for most of the Americas, which is why the eclipse will not be visible from these regions, according to Gordon Johnston, Planetary Program Executive at NASA Headquarters, writing for the NASA Science blog.

penumbral lunar eclipse
The full moon during the penumbral lunar eclipse is seen on the outskirts of Chandigarh, India, on January 11, 2020. VIJAY MATHUR/AFP via Getty Images

The moon is technically considered "full" at specific moments, which on Friday will be 3:12 p.m. ET. At these times, the moon appears opposite the sun and is fully illuminated from the Earth's perspective.

However, to the untrained eye, the moon will appear fully illuminated from early Thursday morning to early Sunday morning, according to Johnston.

In the U.S., Native American Algonquin tribes referred to the full moon in June—the last of spring—as the "Strawberry Moon," according to the Maine Farmer's Almanac. This name is linked to the relatively short harvesting season for strawberries in the northeastern U.S.

In 2020, there will be a total of four lunar eclipses, all of which will be penumbral. The world will have to wait until May 26, 2021 for the next total lunar eclipse, which will be visible from south and east Asia, Australia, much of North America, South America, Antarctica and the Pacific, Atlantic and Indian oceans.

During a total eclipse, the inner, darker part of the Earth's shadow—known as the umbra—falls on the face of the moon. During the maximum of these eclipses, the moon is entirely covered by the umbra, appearing reddish in color due to a phenomenon known as Rayleigh scattering. This is also responsible for the reddish colors seen at sunrise and sunset on Earth, as well as the blue color of the sky during daylight.

During totality, some light from the sun, which is not directly blocked by our planet, is refracted through the Earth's atmosphere and bent onto the moon at a shallow angle, turning it a dramatic reddish color.

During a partial lunar eclipse, only a fraction of the moon is covered by the Earth's umbra, meaning only parts of it are bathed in darkness.