Astronomers can’t be sure about this number, because not all Milky Way stars are visible from the Earth, due to some of them being too far, too faint, or obscured by gas or dust. However, various estimates are available: some based on the shape and size of our Galaxy, others based on our Galaxy’s likely mass. These estimates typically range from 100 billion to 400 billion stars. For comparison, 100 billion is approximately the number of people who have ever lived on Earth.
- How do we know what the Milky Way looks like?
- Are many visible stars dead?
- If the Universe is expanding, why is the Andromeda galaxy on course to collide with the Milky Way?
- When I look to the stars, how far back am I seeing?