The stages of the Super Flower Blood Moon lunar eclipse of 2022 explained

Total eclipses of the moon are the most colorful of all astronomical phenomena.

Each lunar eclipse is unique, with its brightness and coloration determined by a range of factors, such as the geometry of the eclipse and the large-scale meteorological conditions on Earth. When the moon is entering, and later emerging from, Earth’s shadow, secondary phenomena may be overlooked.

To help prepare for the upcoming total lunar eclipse of May 15-16, Space.com’s Joe Rao — a veteran of 19 total lunar eclipses — has prepared a chronology, including some of the things you might see. You may not see everything, as eclipses vary in appearance.

But many of these phenomena will indeed be visible, and observers who know what to look for will have a better chance of seeing the various stages. You can view a webcast of this event if the eclipsed moon is below your horizon or if you have cloudy or bright skies that block your view. Here’s how to watch the Blood Moon total lunar eclipse online.

The May full moon is known as the Flower Full Moon and is occurring when the moon is near perigee, its closest point to the Earth for the month, making it also a so-called supermoon as it can appear slightly larger than when the moon is at its farthest from Earth.

Related: Super Flower Blood Moon lunar eclipse: Is it the 1st of 4 supermoons?

The Super Flower Blood Moon stages

In the above timetable, local circumstances are provided for eight time zones. The moon is still below the horizon when the dashes are displayed.

Here’s a breakdown of the stages of the blood moon total lunar eclipse and what you might see during each one:

1) The moon enters the penumbral shadow

The shadow cone of the Earth has two parts: a dark, inner umbra, surrounded by a lighter penumbra. The penumbra is the outer, pale portion of Earth’s shadow. The eclipse officially begins at this time, but you won’t notice anything extraordinary happening to the moon. Earth’s penumbral shadow is so faint that it remains invisible until the moon is deeply immersed in it, when the penumbra has reached roughly 70% across the moon’s disk. For about the next 40 minutes, the full moon will continue to appear to shine normally, but with each passing minute, it is progressing ever deeper into Earth’s outer shadow.

2) Earth’s penumbral shadow appears

Now, the moon has progressed far enough into the penumbra that it should be evident on the moon’s disk. Look for subtle light shadings to appear in the left portion of the moon. As the minutes go by, the shading will appear to expand and deepen. The penumbra will appear just before the moon enters Earth’s dark shadow.

3) The moon enters Earth’s umbral shadow

Related: How to photograph a lunar eclipse

4) The moon is 75% covered

With three-quarters of the moon’s disk now eclipsed, the part of it that is immersed in shadow should begin to light up very faintly, similar to a piece of iron heated to the point where it just begins to glow. The umbral shadow isn’t completely dark.

In binoculars or a telescope, the outer portion is usually light enough to reveal lunar seas and craters. The central portion is darker and can sometimes be difficult to identify. The umbra’s colors can vary from one eclipse to another. Reds and grays are the most common, but there are also other colors.

5) Less than five minutes to totality

Several minutes before (and after) totality, the contrast between the remaining pale-yellow sliver and the ruddy-brown coloration spread over the rest of the moon’s disk may produce a beautiful phenomenon sometimes called the Japanese lantern effect, a term first coined by astrophotographer Peter A. Leavens in the 1950s.

6) Total eclipse begins

When the last of the moon enters the umbra, the total eclipse begins. It is unknown how the moon will appear during totality. It can appear so dark gray or black during eclipses that it almost disappears from view. It can also glow bright orange during other eclipses. The reason the moon can be seen at all when it’s totally eclipsed is that sunlight is scattered and refracted around the edge of the Earth by our planet’s atmosphere. To an astronaut standing on the moon during totality, the sun would be hidden behind a dark Earth outlined by a brilliant red ring consisting of all the world’s sunrises and sunsets. Global weather conditions and dust suspension in the atmosphere determine the brightness of the ring around Earth. Clear skies on Earth mean a bright lunar eclipse. The eclipse will appear very dark if there has been a major volcanic eruption in the last couple of years.

And indeed, on Jan. 15, there was such an event: the eruption of Hunga Tonga-Hunga Ha’apai, a submarine volcano in Tonga, an archipelago in the southern Pacific Ocean. We won’t know until eclipse night whether this eruption caused the eclipse to appear unusually dark.

For northwestern Oregon, the western half of Washington state, much of British Columbia and the Hawaiian Islands, the moon will rise in total eclipse. These areas will require observers to wait until the sky becomes darkened and the moon rises sufficiently high above the east-southeast horizontal for their first glimpse of the eclipsed lunar disk. Hawaii’s observers will likely not be able to see the moon until it emerges from its umbral shadow.

Related: Why does the moon turn red during a total lunar eclipse?

7) Middle of totality

The moon is now shining anywhere from 10,000 to 100,000 times fainter than it was just a couple of hours ago. Because the moon is moving to the south of the center of Earth’s umbra, the gradation of color and brightness across the moon’s disk should be such that its upper portion appears darkest, with hues of deep copper or chocolate brown. The lower portion of the moon, which is the closest to the umbra’s outer edge, should be brightest. Its hues could include reds, oranges, and perhaps even bluish-white. If you are not near bright city lights, you will see more stars that were earlier in the night.

The moon will appear in the constellation Libra (the Scales), with the entire retinue of bright summer stars and constellations spread out to the north and east of the moon. In the 2022 Observer’s Handbook of the Royal Astronomical Society of Canada, retired NASA astronomer Fred Espenak noted that in 1982, he watched another total lunar eclipse with the moon in nearly the same part of the sky. He said, “I was amazed at how brilliantly summer Milky Way glow since it was almost invisible during the partial stage.”

The darkness of the sky during totality is indeed impressive. The landscape surrounding it has taken on an eerie hue. The full moon was flat and undimensional before the eclipse. The full moon appears smaller and more three-dimensional during totality. It almost looks like a strangely illuminated ball suspended in space.

Before the moon entered Earth’s shadow, the temperature on its sunlit surface hovered at 261 degrees Fahrenheit (127 degrees Celsius). The moon does not have an atmosphere so heat cannot escape into space. Now, in shadow, the temperature on the moon has dropped to minus 146 F (minus 99 C) — a drop of 407 F (226 C) in just over an hour!

8) Total eclipse ends

The emergence of the moon from the shadow begins. The first small segment of the moon begins to reappear, followed again for the next several minutes by the Japanese lantern effect.

For Alaska, only observers in the southeast part of the state will see the eclipse, and only as the moon is gradually emerging from the umbral shadow. The entire eclipse will occur in the Great Land State. Unfortunately, the moon will not be visible to the rest of the Great Land State.

9) The moon is 75% covered

Any vestiges of coloration within the umbra should be disappearing now. As the shadow slowly creeps away from the moon’s disk it will appear black and featureless.

10) Moon leaves umbra

The dark central shadow clears the moon’s right-hand (western) limb.

11) Penumbral shadow fades away

As the last faint shading vanishes off the moon’s right portion, the show comes to an end.

12) Moon leaves penumbra

The eclipse officially ends, as the moon is completely free of the penumbral shadow.

Editor’s Note: If you snap an amazing lunar eclipse photo (or your own eclipse webcast) and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to spacephotos@space.com.

Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers’ Almanac and other publications. Follow us on Twitter @Spacedotcom and on Facebook.

Joe Rao is Space.com’s skywatching columnist, as well as a veteran meteorologist and eclipse chaser who also serves as an instructor and guest lecturer at New York’s Hayden Planetarium. Natural History magazine, Farmers’ Almanac, and other publications publish his astronomy articles. Joe is an 8-time Emmy-nominated meteorologist who served the Putnam Valley region of New York for over 21 years. On Twitter and YouTube, you can follow Joe to track meteor showers, lunar and solar eclipses and other information. Follow Joe on Twitter to find Joe’s latest projects.