---
title: "How many galaxies are there? hundreds of billions — possibly 2"
description: "hundreds of billions — possibly 2 trillion How the figure is estimated, how confident it is, and what makes the scale graspable."
url: https://atoneplace.net/how-many/galaxies-in-the-universe/
site: "At One Place"
---

# How many galaxies are there?

**How many galaxies are there?: hundreds of billions — possibly 2 trillion**

The James Webb deep-field image that covers a patch of sky the size of a grain of sand held at arm's length contains several thousand galaxies.

This is the entry where the experts most visibly disagree. Counting galaxies directly in Hubble deep-field images and scaling to the whole sky gives around 200 billion. A 2016 analysis argued that faint dwarf galaxies push the true total to about 2 trillion, ten times higher. Then in 2021 the New Horizons probe, far enough from the Sun to escape the solar system's dust glow, measured the total background light of the sky and found it consistent with only a few hundred billion. As of now the lower figure is the better-supported one, and the 2 trillion number is still the one most often quoted.

## How the figure is arrived at

Deep-field extrapolation: expose on an empty patch of sky for days, count galaxies, divide by the patch area, multiply by the area of the whole sky. The correction for galaxies too faint to appear is where the disagreement lives. The New Horizons approach sidesteps counting entirely by measuring how much light the sky contains in total and asking how many galaxies it would take to produce it.

## How confident it is

- **Low estimate:** 100,000,000,000
- **High estimate:** 2,000,000,000,000
- **Spread:** 20.0× between the bounds

## 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 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 many constellations are there?](https://atoneplace.net/how-many/constellations/) — exactly 88
- [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 galaxies are there?

hundreds of billions — possibly 2 trillion

### How is that estimated?

Deep-field extrapolation: expose on an empty patch of sky for days, count galaxies, divide by the patch area, multiply by the area of the whole sky. The correction for galaxies too faint to appear is where the disagreement lives. The New Horizons approach sidesteps counting entirely by measuring how much light the sky contains in total and asking how many galaxies it would take to produce it.

## 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 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 constellations are there?](https://atoneplace.net/how-many/constellations/)
- [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

- NASA — National Aeronautics and Space Administration (https://www.nasa.gov/) [Public domain (US Government)]