There is both very big moon news and very small moon news breaking this week—but the one that’s making the headlines is not necessarily the one you would expect. The very big moon news is a paper published today in the journal Science Advances, titled “Indigenous noble gasses in the moon’s interior.” It’s a Swiss-led study of lunar meteorites showing that “unbrecciated lunar mare basalts” reveal traces of “indigenous noble gasses” helium and neon, which they inherited from the Earth’s mantle, adding to the “already strong constraints” showing that the moon was formed by material inherited from the Earth and…and…your eyes are glazing over, aren’t they?
OK, then let’s go with the very small lunar news: The Sturgeon Moon! It’s coming! As has been widely—and somewhat breathlessly—reported all week long, on Thursday, Aug. 11, the fourth supermoon of 2022 will rise in the skies, reaching its peak illumination at 9:36 p.m. ET and putting on what most people consider a flat-out dazzling sky show. But why? What is a supermoon and why all the hoopla?
There are 12 full moons every year and all things being equal, they’d be equally eye-catching. But all things aren’t equal. As I reported in June, during the Strawberry supermoon (which was named by Native American tribes because that month’s supermoon coincides with peak strawberry picking season), the moon is believed to have been formed in violence about 4.5 billion years ago, when a passing Mars-sized planetesimal collided with the Earth, sending a massive cloud of debris into space, which eventually coalesced into the moon and retreated to a stable orbit that averages 382,000 km (roughly 238,000 mi.) from Earth. (The new Science Advances study strengthens that theory by finding earthly gasses in the moon’s interior, showing that the moon is made up at least partly of terrestrial material ejected into space by the ancient collision.)
The moon’s average 382,000 km distance from our planet is not consistent throughout the month, however, since the lunar orbit is not circular, but elliptical, ranging as far away as 406,000 km (252,000 mi) and as close as 357,000 km (222,000 mi). The nearer the moon, the bigger and brighter it appears, and when its closest approach—or perigee—coincides with a full moon, that’s when you get a supermoon. But the “super” designation may be a bit overdone.
At its most luminous, a supermoon can be 16% brighter than an ordinary full moon, which is noticeable, but not huge. And as for apparent size, well, it’s not all that much. As astronomer and director of New York City’s Hayden Planetarium Neil deGrasse Tyson tweeted during last month’s even larger supermoon, “Tonight’s Full Moon, the largest of the year, is 8% larger than an average Full Moon. Will be called by some a ‘Super Duper Moon.’ I’m okay with that, but only if you think a 16-inch pizza is super-duper-sized compared with a 15-inch pizza.”
It’s the people who know astronomy the best—like Tyson—who seem to be the least impressed by what dazzles the rest of us. As I also reported in June, I once asked astronaut Frank Borman, who commanded Apollo 8, the first crewed mission to orbit the moon, if he ever looks up at the moon at night with a bit of wonder, contemplating the improbable fact that he was once there.
“Nah,” he told me with a wave. “I’ve tried that once or twice because people always tell me I should feel like that, but it just doesn’t work.”
Borman wasn’t the only lunar astronaut to fail to get moonstruck. Five months after Apollo 8, Apollo 10 returned for another lunar orbital mission and Gene Cernan, one of the crew members, looked out at the moon just 97 km (60 mi.) below their spacecraft and tried to wax rhapsodic.
“Hey, let me ask you a question,” the cockpit voice recorder captured him saying. “Where do you suppose a planet like this came from? Do you suppose it broke away from the Earth, like a lot of people say?”
“Don’t ask me, babe,” his crewmate John Young responded.
“It sure looks different…” Cernan said, trailing off.
“I ain’t no cosmologist,” Young said, closing the discussion. “I don’t care nothing about that.”
But the rest of us do care plenty. Of all of the objects in the night sky, only the moon is sufficiently close to appear as a disk as opposed to a mere point—close enough to visit, close enough to touch.
“When I go outside and look at the full moon I feel very connected to the universe,” Michelle Thaller, the assistant director of science at NASA’s Goddard Space Flight Center, once told LiveScience. “The moon is so there; it’s a part of our lives; it may have affected the way humans thought about the universe, our evolution as a culture.”
As the late astronomer and author Carl Sagan wrote in his blockbuster book Cosmos: “The reappearance of the crescent moon after the new moon; the return of the Sun after a total eclipse, the rising of the Sun in the morning after its troublesome absence at night were noted by people around the world; these phenomena spoke to our ancestors of the possibility of surviving death. Up there in the skies was also a metaphor of immortality.”
Supermoons are force multipliers for the metaphor—as are other celestial phenomena. The Sturgeon Moon—which also got its name from Native American tribes, because a supermoon that appears in August coincides with peak fishing season for sturgeon in the Great Lakes—will be this year’s final supermoon, but it won’t be the only spectacle on offer tomorrow. Also playing out will be the Perseid meteor shower, which happens once a year, as the Earth passes through the remains of the tail of the Comet Swift-Tuttle, a body that flies through the inner solar system once very 133 years and last came our way in 1992—leaving debris behind that lingers today. And just five degrees to the south of the moon will be an especially bright point of light, which will be Saturn, photo-bombing the Sturgeon Moon.
Tyson might be right that we make too much out of supermoons, and Young may have a lot of people in his camp who “don’t care nothing about” our love of the night sky. But humans aren’t entirely rational beings; we’re aesthetic beings, we’re romantic beings and, as Sagan hinted, we are also frightened beings—haunted by our own mortality and the enormity of a universe we only partly comprehend. If a supermoon serves as a comforting night light, we’ll happily take it.