Difference Between Galaxy and Universe
We talk about universe but do not know what universe actually is. Scientists have made a number of great discoveries about the universe. But still our knowledge is very small about the universe. There is a lot to discover yet. Many people are confused about the universe and galaxy. They think them the same thing. There is a difference between them which should be clear.
Our earth and solar system are tiny specs in the universe which is vaster than we can imagine. The universe is much beyond we can see from the earth. The earth is insignificant in the universe. It is a small point in the vast sea. Our solar system has 9 planets. The solar system is situated in a galaxy which is another name of Milky Way. There are a large number of such galaxies exist in the universe about which we have little knowledge. Our galaxy consists of about 200 million stars. Many of them are many times bigger than the sun. Thus we can imagine the vastness of the universe.
The universe is much bigger. A galaxy is just a small particle of the universe. The Milky way in which our solar system is situated is one of about 170 billion galaxies in the universe. A galaxy contains a large number stars which are bound together with the help of gravitational force. The galaxies vary in their size and the number of stars they contain. The number of stars in a galaxy may vary between ten million and a hundred trillion. The number is mind boggling. And all that is the part of the entire universe. A galaxy contains a number of stars which may be many times bigger than our sun. And there are millions of such galaxies in the universe. The vastness of universe is unimaginable. Thus we can see that how little of our knowledge is about the whole universe.