How Many Stars Are There In The Universe?

A simple answer could be ‘We don’t know!’ Certainly, there exists estimates that there might be that many stars in the universe but that is a rather broad band of numbers, like minimum this many and maximum that many, but not an exact figure.

The question has been around for quite a long time. from times since man got civilized, to our present times, each generation of philosophers, scientists, inquisitors have asked this question and the answers have varied with each generation!

Let’s try to figure out ourselves how many stars are there above us, by counting them all on a dark night. This is what the ancients did and they found that there were around 2500 shining objects in the sky. They also noticed that some of those shining objects had peculiar motions, they are now called planets!

The interest continued and each civilization contributed to the subject. The Chinese, the Indians, the Mayans, the Babylonians, the Egyptians, the Persians, the Arabs, the Greeks—each civilization devised its own ways to study the heavens and as often happens in science, a lot of these ways were invented many times independent of each other.

Then came the age of Renaissance in Europe; the Europeans understood the value of education and began studying. A famous scientist of those times was Galileo Galilee, also credited as the first person to turn the telescope towards the skies. And the stars multiplied, overnight! Yes, use a small telescope and you, yourself will find out that from mere 2500 objects previously, more than a million objects will now come into your view!

But counting them manually is not easy because it turns out that some of them are galaxies. Stars are not evenly distributed evenly in the universe but they come in clusters and those clusters are known as galaxies. Our own little yellow star, the Sun, belongs to the Milky Way galaxy. It has been estimated that the Milky Way alone has somewhere around 100 billion to 1000 billion stars in it. Again, as we said, it is a band of numbers, and not an exact figure.

And to reach to that figure scientists have devised a clever way around— counting them indirectly. The basic principle applied is this: to calculate how many people there are in a theater, one need not count them individually. Just count the number of rows and how many people a row can accommodate, and then multiply those numbers and you will have the number of people in the theater. This is called indirect counting.

Scientists applied the same principle, of course, in a more refined manner. After calculating the number of stars in a particular area, they thus found the average density of stars in our galaxy. Then they put the numbers in an equation and hurrah! The result was 100 billion to 1000 billion stars!

What the scientists have found is – almost the same number of galaxies (100 billion to 1000 billion) exists in our universe. Taking our own galaxy as a typical example, we will just have to multiply the number of stars in our galaxy to the number of galaxies known to get a rough estimate of the number of stars in our universe. It calculates out be approximately 10 followed by 22 zeros, that is, 100 000 000 000 000 000 000 000 or 100 billion trillion stars!

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