Retired NASA eclipse scientist Fred Espenak has been watching the night sky since he was eight years old and plans to search for the next lunar eclipse again on Sunday, May 15.
After roughly six decades of gazing at the sky, the Arizona resident said he still enjoys watching the shading change as the moon turns red during a total lunar eclipse, fully stepping into the deep shadow of Earth. Read our complete Super Flower Blood Moon lunar eclipse guide to prepare for the epic lunar event.
Webcasts: How to Watch Super Flower Blood Moon Lunar Eclipse Online
“You look at it 10 seconds before or 10 seconds after, you can’t tell the difference,” Espenak told Space.com of lunar eclipses. “It’s more of a gradual effect. Minute by minute you can see changes, but second by second you can’t.”
The Flower Moon eclipse will be visible in full phase from parts of the Americas, Antarctica, Europe, Africa and the Eastern Pacific. This eclipse will feature a moon that appears slightly large, on the verge of supermoon status. If you’re hoping to photograph the moon or want to prepare your gear for the total lunar eclipse, check out our best cameras for astrophotography and our best lenses for astrophotography. Read our guides on how to photograph a lunar eclipse, as well as how to photograph the moon with a camera for some helpful tips for planning your lunar photoshoot.
Not everyone agrees that the Full Flower Moon is a supermoon due to varying definitions. Espenak’s definition is based on the very first supermoon, when astrologer Richard Nolle in 1979 defined it as a full moon that is less than 90% from its closest orbiting point to Earth.
“That’s the definition I use, because it was the first. As far as I’m concerned, it sets a precedent,” he said. “But first of all, that 90% is purely arbitrary. There’s no real justification why it should be 90%, or 89 or 91.”
But Espenak calculates supermoons to also account for changes in the moon’s orbit during each lunar cycle, including perigee (closest point) and apogee (farthest point). NASA, which follows the strict 90% definition, says the Flower Moon is not a supermoon, but the June full moon will be.
Espenak’s rationale boils down to lunar variability. “The perigee point and the apogee point of each [moon] the orbit varies from orbit to orbit,” he said. This is because Earth and the sun’s gravity pull the moon into its orbits.
“The limits of what you get as a supermoon vary from orbit to orbit,” he added. “So in order to determine whether a particular moon is a supermoon or not, you have to look at the moon’s specific orbit during that lunation cycle.” (A lunation is a lunar month, or the time between new moons.)
Epsenak’s definition of a supermoon will place the next four full moons in a row as supermoons: May 16, June 14, July 13, and August 1. 12. But he noted that the footage isn’t particularly rare. According to its website, 2023 will also see four full supermoons in a row, just like 2024. Even 2025 has three in a row.
“Every 14 months or so, you get a string of moons that exceed that 90% threshold. So very often, every 14 months or so, we get two or more, probably three to four,” he explained. He added that the relative size of the largest full moon is so small, however, that even he cannot easily tell the difference just by looking at the sky.
While the size of the supermoon will be subtle, the eclipse will get quite interesting once it reaches the first umbral contact with the moon. The penumbral or lighter eclipse introduces a subtle nuance, but the shadow, Espenak said, “will look like the Cookie Monster has taken a piece” of the moon.
“You don’t really see the color until you get close to totality,” he said. The blood moon, he added, should be very easy to spot within minutes of totality, although that will depend on the lighting and atmospheric conditions in your area.
“In dark places, it’s easier to detect subtle colors and features,” he said. “Sharp-eyed observers will notice that the part of the moon that is deep in shadow, they will be able to see some color there in the last five to 10 minutes of the partial phases as we approach totality.”
The Blood Moon, however, may not look exactly red. “It ranges from bright orange, to fire truck red, to a dark brown color, all the way to an almost invisible dark gray brown,” Espenak said. “Most of the time, though, it’s orange to red, and that’s because of the colors caused by sunlight filtering through Earth’s atmosphere.”
Although the timing depends on your location, TimeandDate.com indicates that the partial eclipse phase of the lunar eclipse begins May 15 at 10:28 p.m. EDT (0228 GMT on May 16). It will reach the red peak of the Blood Moon on May 16 at 12:11 a.m. EDT (0411 GMT). The event ends at 1:55 a.m. EDT (05:55 GMT). Note that the penumbral eclipse will start about an hour earlier and end about an hour after the partial eclipse.
Editor’s note: If you take a great lunar eclipse photo (or your own eclipse webcast) and want to share it with Space.com readers, please submit your photo(s), comments, and your name and location to firstname.lastname@example.org.