Black Moon

While the Sun is invariably the most important body in space, an argument could easily be made that humans care more about the Moon. The queen of the night sky, we’ve looked at our satellite with awe for millennia. The ability to look at the Moon might be why we give it more love than the Sun. We need total eclipses or special equipment to take a gander at our burning ball, but Luna shines kindly on our eyes. Her changing appearance also adds to the allure.

Our ancestors dedicated a lot of time to studying the Moon and giving its many flavors names. Each month’s Full Moon snagged a nickname. August’s version, for example, is the Sturgeon Moon. The correlation between a month and a lunar cycle is not accidental: we based our “moonth” on the Moon! But when we developed that system, our abilities to be precise weren’t as good as they are today. The cycle is not quite 30 or 31 days, nor is it 1/12 of a solar year, but slightly shorter at 29.5 days. This discrepancy leads, every so often, to two Full Moons in a calendar month. Of course, we named this phenomenon, as well; it’s a Blue Moon.

A Full Moon gets the most attention, but we also have monikers for the other phases.

Waxing crescent. First quarter. Waxing gibbous. Waning gibbous. Third quarter. Waning crescent.

And, the start and end of each cycle, the New Moon.

The New Moon gets the least love. It makes sense; this phase occurs when the Moon is between the Earth and the Sun, meaning we can’t see it happening. The Moon is, of course, still there, but it rises along with the Sun, and, since all the light hits the far side, we can’t see the Moon at all during this stage.

Just because it’s invisible doesn’t mean we haven’t taken the opportunity to add to the long list of Moon nicknames.

If two Full Moons can transpire during one month, it stands to reason that two New Moons can also pop up.

And, yes, we have a name for that.

We call the second New Moon during a calendar month a Black Moon!

The image above is not technically a New Moon, but the earliest possible post-New Moon we could see.

Thinking about whether we can see New Moons is not as simple as you might first imagine. Thinking about the position of the Sun-Moon-Earth system at a New Moon, you’d think we could not see our satellite, as only the far side is illuminated by the Sun. However, the side closest to us actually receives light that bounces off the Earth! The amount of Earthshine is more than enough for us to spy the Moon in a vacuum; however, we still can’t see the New Moon because it rises in our view during the day. The Sun produces so much light that it occludes our ability to detect that Earthshine.

So, has anyone ever seen a New Moon and, by extension, a Black Moon?

Yes, many!

If you’ve ever witnessed a total solar eclipse, you’ve seen a New Moon. One of nature’s grandest displays occurs only when a New Moon completely obscures the Sun’s disk. The black circle that appears inside dancing light is the New Moon!

Has a Black Moon ever been the culprit of a total solar eclipse?

Digging for explicit confirmation from astronomers was difficult, but I found four dates in the second half of the 20th century where a total solar eclipse and a black moon aligned:

So, certain people have seen a Black Moon!

The next conjunction between a total solar eclipse and the second New Moon of a month will happen in March 2033. If you want to catch that special event, you’ll need to visit Far East Russia or Alaska.

BONUS FACT: Since the lunar cycle is 29.5 days long, one particular month can’t feature a Black Moon or a Blue Moon: February! Further, some Februaries don’t have a single New Moon or Full Moon. If one occurs at the end of January, the timeline might take the next one all the way to March. February 2033 – just before the next total solar eclipse and Black Moon meeting – will not have a New Moon; February 2037 won’t have a Full Moon.