Have you ever looked up into the night sky and wondered just how many stars there are in space. On a dark night with good viewing conditions, you might be able to see about 4,000 stars with the naked eye.
Imagine, then, if you could see a million stars with the naked eye. So how many stars are there in the Universe?
It has been said that counting the stars in the universe is like trying to count the number of sand grains on a beach on Earth. We might do that by measuring the surface area of the beach, and determining the average depth of the sand layer.
If we count the number of grains in a small representative volume of sand, by multiplication we can estimate the number of grains on the whole beach.
Stars are not scattered randomly through space, they are gathered together into vast groups known as galaxies. Our sun belongs to a galaxy called the Milky Way.
Astronomers estimate there are about 100 thousand million stars in the Milky Way alone. Outside that, there are millions upon millions of other galaxies.
A very rough estimate is of 10 trillion galaxies in the universe. Multiplying that by the Milky Way‘s estimated 100 billion stars results in a large number indeed:
1,000,000,000,000,000,000,000,000 stars, or a 1 with 24 zeros after it (1 septillion in the American numbering system; 1 quadrillion in the European system).