There’s a “black moon” rising, but don’t start howling just yet — there won’t be much to see.
The sky in the Western Hemisphere on Friday will feature what some astronomy aficionados call a “black moon,” or simply the second new moon in a single month. New moons typically occur just once a month since the lunar cycle is 29.5 days, but the phenomenon happens when new or full moons occur on the first day of any month except February. They generally occur roughly every few years, but outside of a catchy moniker, there’s really not much to them, astronomers told The Post.
“There’s no astronomical definition for them,” said Derrick Pitts, chief astronomer at Philadelphia’s Franklin Institute. “There’s no scientific validity to them at all, but it’s taken on some cultural validity lately.”
Like blood moons and blue moons, Pitts said so-called “black moons” have become popular in mainstream culture but are technically not astronomical terms. Sky-watchers frequently use terms to identify what they see and sometimes the phrases catch on, sometimes they don’t, he said.
“’Black moon’ sounds much more dramatic than ‘the second new moon of the month,’” Pitts said. “It just sounds dramatic: ‘There’s a black moon rising.’ That’s a great way to stir up scary images, bad omens, all sorts of stuff like that. A great way to generate some fear, too.”
So don’t worry, the apocalypse is not close behind. In fact, you won’t even be able to see the lunar oddity.
“This is not a visible phenomenon,” Pitts said. “A lot of people are going to be frustrated because you can’t go see the black moon. You just can’t do that.”
Joseph Patterson, an astronomy professor at Columbia University, echoed Pitts’ take on black moons, saying most astronomers simply don’t care about them.
“There’s a black moon rising. That’s a great way to stir up scary images, bad omens, all sorts of stuff like that. A great way to generate some fear, too.”
- Derrick Pitts, chief astronomer, Franklin Institute
“I don’t think astronomers care about them,” he told The Post. “It’s more of a curiosity, really. It might mean something in astrology, but not in astronomy.”
But as with all new moons, the naked eye won’t be able to get a glimpse, since that’s when the moon’s dark side faces Earth. New moons can only be seen during solar eclipses — the next one visible in North America is in August — or during the days just before or after a new moon when you can see a thin crescent.
“That’s the closest you can really get to seeing a new moon,” Patterson said.
Along with a new moon, Patterson said, comes a higher tide, sometimes by as much as 2 feet. So if that coincides with a major storm system, it can produce a significant surge, he said. Otherwise, black moons have no real astronomical value.
“They’re only important in that’s interesting and useful to know the phases of the moon and when they occur,” said Bruce Betts, director of science and technology at the California-based Planetary Society. “They have no other astronomical significance.”
Betts said black moons occur about once every three years, with fluctuations due to differences between the lunar cycle and the Gregorian calendar. The last ones occurred in 2014, in both March and January.
“On average, it’s about once every two or three years because our calendar is not consistent in what we define as a month,” Betts said.
Space.com reports the figure is closer to once every 32 months, with Friday’s black moon occurring at 8:11 p.m. ET in the Western Hemisphere. However, for the Eastern Hemisphere, including Europe, Africa, Asia and Australia, the new moon happens after midnight on Oct. 1 — and is therefore the first new moon of the calendar month.
“So it does not qualify as a Black Moon, and that hemisphere will have to wait until the end of the month for theirs,” Space.com reports. “Indeed, for the billions living in the Eastern Hemisphere, the Black Moon will arrive on Oct. 30 or, if you live in eastern Asia, Japan, Australia or New Zealand, not until Oct. 31 (Halloween).”
NationalGeographic.com suggests that the black moon might be considered the “evil twin” of a blue moon, or the second full moon in a month.
“But let’s be clear: This new moon — like any astronomical event — doesn’t bring ill tidings or herald the end of days, despite the astrological fear-mongering that has been seeping through the web,” NationalGeographic.com reports.
The Daily Express reported Wednesday that the black moon “could bring with it worldwide destruction and the second coming of Jesus Christ,” citing claims by Christians and conspiracy theorists on Facebook. Scientists, meanwhile, said there’s “nothing to fear,” the newspaper reported.
Betts, meanwhile, said the rare lunar event is merely just another good time to look skyward.
“Anytime there’s a new moon, it’s a great time to go look at the night sky because the moonlight is not interfering with seeing the stars and other deep sky objects,” he said. “It’s a great time to look.”