Eclipse science · Modern symbolism
Blood moon meaning: the science and the symbolism
A blood moon is a total eclipse of the Moon, when Earth's shadow covers it and it glows red. The physics is simple and lovely. The symbolism is modern, and varied. Here are both, kept apart.
What a blood moon is
A lunar eclipse happens when the Sun and Moon are on precisely opposite sides of Earth, so Earth blocks sunlight from the full moon; it can only happen at full moon. In a total eclipse the Moon is still faintly lit, because some sunlight bends through Earth's atmosphere on the way. In NASA's words (opens in a new tab), the eclipsed Moon is lit by red-orange light left over from all the sunrises and sunsets happening around the world at that moment. How red it gets depends on Earth's air, and it is graded on a scale of nought to four. It is safe to watch with your own eyes.
The next ones
The next total eclipses of the Moon in this site's eclipse table, from NASA's canon:
Each page says where on Earth it can be seen.
Other things called blood moon
The name wanders. The full moon after the Harvest Moon, the Hunter's Moon, is sometimes called the Blood or Sanguine Moon, which NASA's full moon guide (opens in a new tab) puts down to the hunting season or the reddening leaves, not to its colour. And any full moon low on the horizon can look orange, because its light crosses more air; that is not an eclipse.
What astrologers make of it
In modern astrology a lunar eclipse is read as a full moon with the volume turned up. At Astrology.com lunar eclipses are super-powered full moons (opens in a new tab) about letting go, sudden course corrections and things that no longer serve you, tied to the Moon's nodes; many practitioners advise against wishing or ritual work during one, a rule documented on the Historical beliefs side as the rule against wishing on an eclipse. That rule inherits a much older habit of reading eclipses as omens, from Babylon to Mesoamerica.
What an eclipse cannot tell you
An eclipse is geometry that astronomers predict centuries ahead. It happens to the whole half of the planet that can see it at once, and it says nothing about any one person's future. There is nothing to fear in it and nothing you have to do. The red on this page is the colour of this section of the site; it does not mean an eclipse is happening now.
Sources
Practitioner sources tell you what those practitioners say. They are not evidence that the Moon does it.
- Astronomy NASA Science, Super Blood Moon: Your Questions Answered (2021) (opens in a new tab) for what a total lunar eclipse is, and why the eclipsed Moon turns red
- Astronomy NASA, May 2022: The Next Full Moon is the Flower Moon, by Gordon Johnston (archived copy) (opens in a new tab) for Blood or Sanguine Moon as a name for the Hunter's Moon, and why
- Practitioner Stephanie N. Campos, Lunar Eclipse and Solar Eclipse, Astrology.com (opens in a new tab) for lunar eclipses in modern astrology: letting go, course corrections, the nodes