How Many Stars Are in the Universe
Outer-space is considered infinitely big, meaning that even if it does end somewhere, that place is so far away that we’ll probably never know it exists! In order to study about outer-space more easily, scientists divide it up into “galaxies,” which refer to the groupings of millions of stars and particles of dust and gas that are all in one place together. Earth, for example, is in the Milky Way galaxy.
When it comes to how many stars there are in the universe, it’s impossible to know any kind of exact number since the universe is really just that big! In the Milky Way galaxy alone, scientists estimate that there are between 100-200 billion stars!
Estimates for how many stars there are in the entire universe change as our technology to figure it out changes too. Usually, the estimates are calculated by multiplying the number of stars believed to be in the average galaxy by the number of galaxies in the known universe, which is 80-100 billion. – Using research applied to formulas like these, many researchers are currently saying there are somewhere from 10 to 70 sextillion stars in the universe, but could easily end up soon realizing that it’s even more!
Did you know?
Have you ever stared up at the stars in the night sky and wondered how many there are? If so, you’re not alone. That question has fascinated astronomers, artists and dreamers of all ages since the beginning of time.
Famous astronomer Carl Sagan once estimated that there must be “billions upon billions” of stars in the universe. If you’ve ever tried to count the stars in the night sky, you may have concluded that it would be impossible to count them all.
Guess what? You’d be absolutely right!
Before we get to the mind-boggling estimates that modern astronomers have made, let’s start “small” and get some perspective. We live on planet Earth, which orbits around a star we call the sun.
The Earth and the sun, along with several other planets, make up a solar system, which is part of a larger grouping of stars called a “galaxy.”
Our particular galaxy is known as the Milky Way. Scientists estimate that there are 200 billion to 400 billion — yes, that’s billion with a “b” — stars in the Milky Way galaxy. Our sun is just one of those 200 billion to 400 billion stars.
If that blows your mind, just wait! Our Milky Way galaxy is just one of the many galaxies in our universe.
How many? Believe it or not, astronomers estimate there are 100 billion to 200 billion galaxies in the universe, each of which has hundreds of billions of stars.
If your mind is reeling, that’s OK. It’s hard for most people to imagine the size of the universe. Check out this video if you want to see how one person tries to put the size of the universe into perspective.
So how many stars are there? In truth, there are too many to count. Current estimates are just guesses.
Even using our most advanced telescopes and technology, we still cannot see to the ends of our universe. Further complicating things, closer stars that are particularly bright also block our ability to see beyond them in certain directions.
Scientists use observations and data we do have, along with assumptions about our galaxy and the other galaxies in the universe, to estimate the number of stars. Recently, though, some scientists challenged some of the assumptions scientists have been using for years.
The result? Scientists now believe there may be three times more stars than scientists previously estimated.
Why? Astronomers now believe there may be many more red dwarf stars — the most common type of star in the universe — than previously thought.
Based on the latest estimates, astronomers estimate our universe could be the home to 300 sextillion stars. Just how many is that? This many:
That’s a 3 with 23 zeroes after it. Any way you look at it, that’s a lot of stars. As technology improves and we get even better glimpses at the far corners of the universe, we may eventually find that the number of stars is even greater than anyone could ever imagine!