Bernard Rivera


The Number of Stars

Posted by Bernard Rivera on

How Many Stars Are Out There

It’s an often asked question – How many stars are in the universe? Well it’s a bit hard to imagine.

The Star we know About

Our Sun
Our star, the sun, is considered to be a fairly normal sized star a far as stars go – one of the crowd.
But our little star pumps out enough heat and energy, every day, to make temperatures very hot, especially in those summer months. And our sun does this from an incredible 93 million miles away.

And we only get a small fraction of all this energy that the sun generates 24/7. And most of that energy fritters away into the cold reaches of space.

Our Galaxy

a galaxy
But I’ve gone off point. How many stars are there in the universe. Well we obviously can’t count them and this year’s estimate won’t be the same as next year’s estimate. But what we can say is that the estimate will go up. That’s been the trend up to this point and I can’t see the estimates going down any time soon.

But if we start of with our galaxy you’re get an idea of the true enormity and scale. Our galaxy contains at least 150 billion stars (That’s billion not million) and that’s the low estimate. It’s not known with any great accuracy. But it could be as high as 450 billion stars in our galaxy.

As our galaxy is a rather typical galaxy, as far as galaxies go, rather than ask how many stars why not ask how many galaxies instead?

All Galaxies

stars in the milky-way
Again the number of galaxies in our universe can only be estimated with a large margin of error. But at the time of writing the estimate for all the galaxies in the universe is 2 trillion. We’ve entered the world of truly big numbers.

If each of those galaxies has 100 billion stars then the number of stars is 100 billion trillion.

To put some perspective on this if you grab a handful of sand on the beach, you already know you’ve got a lot of sand, thousands, of not tens of thousands of grains of sand in the palm of your hand.

Now imagine that you could count all of the sand on that beach on every beach in the world in the oceans and the seas and all of the deserts as well. That’s a truly colossal amount of sand. But all those grains of sand would be less than the number of stars in the universe.

glass of waterLet’s go really Small

Now let’s take it to the other extreme. A glass of water contains a lot of H2O molecules. If fact it contains more molecules than all the stars in the universe and all the grains of sand countered together.

What an amazing place the universe is!