---
title: "How many constellations are there? exactly 88"
description: "exactly 88 How the figure is estimated, how confident it is, and what makes the scale graspable."
url: https://atoneplace.net/how-many/constellations/
site: "At One Place"
---

# How many constellations are there?

**How many constellations are there?: exactly 88**

The twelve zodiac constellations are a subset of the 88. The Sun actually passes through thirteen, including Ophiuchus, which astrology ignores because the zodiac was fixed before the boundaries were.

There are exactly 88 constellations, because in 1922 the International Astronomical Union decided there would be. Before that the sky was a mess of overlapping and competing figures — astronomers had invented Machina Electrica, Felis the cat and Officina Typographica, among dozens of others, and none of them had agreed boundaries. In 1930 Eugène Delporte drew precise borders along lines of right ascension and declination so that every point in the sky belongs to exactly one constellation. A constellation is therefore now a region, not a pattern of stars.

## How the figure is arrived at

Not a measurement at all — a committee decision, then a cartographic exercise. Delporte's boundaries were drawn for the epoch B1875, so precession has since tilted them slightly relative to today's coordinate grid, and modern star charts show them as very slightly skewed rectangles.

## Other space and the universe counts

- [How many stars are there in the universe?](https://atoneplace.net/how-many/stars-in-the-universe/) — about 200 billion trillion
- [How many stars are there in the Milky Way?](https://atoneplace.net/how-many/stars-in-the-milky-way/) — between 100 billion and 400 billion
- [How many atoms are there in the universe?](https://atoneplace.net/how-many/atoms-in-the-universe/) — about 10^80
- [How many galaxies are there?](https://atoneplace.net/how-many/galaxies-in-the-universe/) — hundreds of billions — possibly 2 trillion
- [How many satellites are in orbit?](https://atoneplace.net/how-many/satellites-in-orbit/) — about 12,000 active satellites
- [How many moons are there in the solar system?](https://atoneplace.net/how-many/moons-in-the-solar-system/) — about 900 confirmed, and the number keeps moving
- [How many planets are there in the galaxy?](https://atoneplace.net/how-many/planets-in-the-milky-way/) — at least 100 billion — probably more planets than stars
- [How many stars can you see with the naked eye?](https://atoneplace.net/how-many/stars-visible-to-the-naked-eye/) — about 9,000 over the whole sky; roughly 2,500 at once
- [How much space junk is there?](https://atoneplace.net/how-many/space-debris/) — about 40,000 tracked objects, and over 130 million fragments too small to track
- [How many asteroids are there?](https://atoneplace.net/how-many/known-asteroids/) — about 1.4 million catalogued

## Common questions

### How many constellations are there?

exactly 88

### How is that estimated?

Not a measurement at all — a committee decision, then a cartographic exercise. Delporte's boundaries were drawn for the epoch B1875, so precession has since tilted them slightly relative to today's coordinate grid, and modern star charts show them as very slightly skewed rectangles.

## Related pages

- [How many stars are there in the universe?](https://atoneplace.net/how-many/stars-in-the-universe/)
- [How many stars are there in the Milky Way?](https://atoneplace.net/how-many/stars-in-the-milky-way/)
- [How many atoms are there in the universe?](https://atoneplace.net/how-many/atoms-in-the-universe/)
- [How many galaxies are there?](https://atoneplace.net/how-many/galaxies-in-the-universe/)
- [How many satellites are in orbit?](https://atoneplace.net/how-many/satellites-in-orbit/)
- [How many moons are there in the solar system?](https://atoneplace.net/how-many/moons-in-the-solar-system/)
- [How many planets are there in the galaxy?](https://atoneplace.net/how-many/planets-in-the-milky-way/)
- [How many stars can you see with the naked eye?](https://atoneplace.net/how-many/stars-visible-to-the-naked-eye/)
- [How many people are there in the world?](https://atoneplace.net/how-many/people-alive-right-now/)
- [How many countries are there in the world?](https://atoneplace.net/how-many/countries/)
- [How many bones are in the human body?](https://atoneplace.net/how-many/bones-in-the-human-body/)
- [How many grains of sand are there on Earth?](https://atoneplace.net/how-many/grains-of-sand-on-earth/)
- [How many ants are there in the world?](https://atoneplace.net/how-many/ants-on-earth/)
- [How many trees are there in the world?](https://atoneplace.net/how-many/trees-on-earth/)

## Sources

- Wikidata — Wikimedia Foundation (https://www.wikidata.org/) [CC0 1.0]