What is a Black Moon?

What is a Black Moon?

There are blood moons and blue moons, and Harvest Moons, but what is a black moon?

The second new moon in a calendar month, or the fourth new moon in a 3-month season, is  sometimes called a black moon.

In the Western Hemisphere on  Friday, September 30, there will be a  black moon.

Can you see the black moon?  Although the moon will turn new on Friday, September 30 at 8:11 p.m. Eastern time, even if it’s a clear night, we won’t be able to see it.  According to EarthSky,  a new moon occurs  when the moon’s Earth-facing side is fully in shadow.

What is the earliest visible sighting of a new moon?  According to Sky  & Telescope–

The record for the youngest Moon ever seen with optical aid, 11h 40m past new, goes to Mohsen G. Mirsaeed of Tehran who saw it on September 7, 2002. The youngest crescent ever seen by the naked eye, 15h 32m, is still that observed in May 1990 by Sky & Telescope contributing editor Stephen James O’Meara.

You can read more about the thin crescent  moons  at Sky &Telescope, here.

What is the significance of a new moon?     The sighting of the new moon marks  important  holidays  in the Muslim calendar.  In Western astrology, a new moon signifies new beginnings.

You can read more about the black moon at EarthSky, here.

Read more about a blood moon here.

Read more about a blue moon, here.

And, here’s more about the full Harvest Moon.




Like this? Why not subscribe? Type your email address in the box and click the “create subscription” button. My list is completely spam free, and you can opt out at any time.

If you have Gmail, don’t miss out. Check your “promotions” box. Move one of my posts from the “promotions” box to “primary” and you’ll never miss a post. Thanks for reading!

Filed under: seasons, weather

Tags: black moon, blue moon, new moon


Leave a comment
  • I wish I was as knowledgeable about astronomy and weather as you are. I admire it!

  • In reply to Kathy Mathews:

    Thanks for reading, Kathy! I so enjoy your postings, too. I always learn from you!

  • I noted that the Chabad calendar did not have a notation for this new moon, even though in other months it has a notation, such as Oct. 31, "3:24-5/18 am," yet the lunar New Year starts the evening of Oct. 2. I guess one can't trust everything.

  • In reply to jack:

    Happy New Year, Jack! I was surprised to learn the new moon is not visible--it is hours later that a crescent of light can be seen. It is the sighting of this crescent that marks the calendar and the holidays. In the Western Hemisphere, the moon turned new on the evening of September 30. In the Eastern Hemisphere, this was October 1. On October 2, the thin crescent of a new moon would be visible in Europe and the Middle East.

  • In reply to Weather Girl:

    So based on your last sentence, I was a bit too hasty then?

  • In reply to jack:

    Your calendar is correct, Jack. According to the Moon Phase Calendar, the moon of October 2 is considered a new moon, 2 days old, 3% illuminated. Sunset today is 6:30 p.m. and the moon sets at 7:37 p.m. according to Tom Skilling's Weather page. It's overcast here, so we probably wouldn't see much, but under ideal conditions, a very thin crescent moon would be visible.

  • In reply to Weather Girl:

    I was going more on "in ... the Middle East" in your prior response, but the linked calendar is a bit ambiguous, in that how can it be new if it aged 2 days? But Sept. 30 was "age 30 days." Sounds like the green cheese got a little more green, sort of like what happens in my refrigerator.

  • In reply to jack:

    Yes, it is confusing! You're right that the Hebrew calendar is based in the Middle East. Both the Hebrew and Chinese lunar calendars do not depend on an actual sighting of a crescent moon. For the Islamic calendar, the first sighting of the crescent moon is often disputed.

Leave a comment