Retired NASA eclipse scientist Fred Espenak has been watching the night sky ever since he was eight years old, and plans once again to look up for the forthcoming lunar eclipse Sunday (May 15).
“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 gradual. You can see the changes from minute to minute, but not second to second. “
The Flower Moon‘s eclipse will be visible in total phase from portions of the Americas, Antarctica, Europe, Africa and the east Pacific. This eclipse will feature a moon that appears slightly large, at the edge 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 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 to plan out you lunar photo session.
Not everyone agrees that the full Flower Moon is a supermoon due to varying definitions. Espenak’s definition is based on the first-ever supermoon, when astrologer Richard Nolle in 1979 defined it as a full moon that comes within 90% of its closest point in the orbit to Earth.
“That’s the definition that I use, because that was the first one. He said, “That sets the precedent.” “But first of all, that 90% is purely arbitrary. There’s no real justification for 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 the perigee (closest point) and apogee (furthest point). NASA, which follows the strict 90% definition, says the Flower Moon is not a supermoon, but that June’s full moon will be.
Espenak’s rationale comes down to lunar variability. He stated that the perigee and apogee points of each orbit [moon] vary from one orbit to another. This is because of the Earth’s gravity pull and the sun’s gravitational pull on the moon through its orbits.
“The limits of what you get as a supermoon varies from one orbit to another,” he added. To determine if a moon is a supermoon, one must look at its orbit during the lunation cycle. A lunation is the lunar month that occurs between new moons. )
Epsenak’s definition of supermoon will put the next four full moons in a row as supermoons: May 16, June 14, July 13 and Aug. 12. He noted that this streak is not unusual. Per his website, 2023 will also see four consecutive full supermoons, as will 2024. Even 2025 has three in a row.
“Every 14 months or so, you get a series of moons that are further than that 90% threshold. So very often, every 14 months or so, we get two or more likely three to four,” he explained. He explained that the relative size between the smaller full moon and the larger one is so small that it’s difficult to tell the difference by simply looking at the sky.
While the supermoon’s size will be subtle, the eclipse will become quite interesting once it reaches the first umbral contact with the moon. Although the penumbral, or lighter eclipse, introduces subtle shading to the umbra. Espenak stated that the umbra will look like “The Cookie Monster” has taken a chunk out of the moon.
“One doesn’t really see the color until you’re getting close to totality,” he said. He said that the Blood Moon should be visible within minutes of totality. However, this will depend on your local lighting and atmosphere.
“In dark locations, its easier to detect subtle colors and features,” he said. “Sharp eyed observers will notice that the part of the moon that’s deep in the shadow, they’ll be able to see some color to it in the last five to 10 minutes of the partial phases as we approach totality. “
The Blood Moon, however, may not look exactly red. Espenak stated that the Blood Moon can look anything from bright orange to fire truck red to dark brownish to almost invisible dark gray. Espenak said that most of the time it is orange-red due to the sun’s rays filtered through the Earth’s atmosphere. “
While timing depends on your location, TimeandDate.com says the partial eclipse phase of the moon eclipse begins May 15 at 10: 28 p.m. EDT (0228 GMT on May 16). It will get to the red-hued Blood Moon peak May 16 at 12: 11 a.m. EDT (0411 GMT). The event ends at 1: 55 a.m. EDT (0555 GMT). The penumbral eclipse will start an hour earlier than the partial eclipse and finish an hour later.
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 firstname.lastname@example.org.
Elizabeth Howell, Ph.D., is a contributing writer for Space.com since 2012. She is proud Trekkie and Canadian and writes about spaceflight, diversity and science fiction to help others explore the universe. Elizabeth has reported on two human spaceflight launches from Kazakhstan and embedded reporting from a simulated Mars mission. She holds a Ph.D. and M.Sc. She holds a Ph.D. in Space Studies from the University of North Dakota and a Bachelor of Journalism at Carleton University, Canada. NASA Leadership Moments is her latest book. She co-authored it with Dave Williams, an astronaut. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday.