Earth is an average planet with a diameter of 12,700 km. But a thousand Earths could be stacked on another planet, Jupiter. A thousand Jupiters in the sun. Or the sun could cover one million Earths with a diameter of 1.39 million kilometers. Look at how small the earth is in comparison. If the sun is an ordinary star. There are stars that are about 1200 times the radius of the Sun.
There are also stars about two thousand times the size of the Sun. A constellation is made up of many stars. Our Milky Way galaxy alone is estimated to contain hundreds of billions of stars. There are also many star clusters. Ours is an average star community. They are many times larger and smaller than the Milky Way. There are thousands / two thousand million such galaxies. There are those who think that the universe is infinite in size – endless. But that thought doesn’t make much sense. It’s hard to understand how that is. Light traveling at 3 million kilometers per second is the distance traveled in 4 years – 4x365x24x60x60 km – the average distance from one star to another.
The diameter of the Milky Way is about 100,000 light-years. It is about 1,000 light-years across and contains about 2 billion galaxies. So what is the diameter of the universe? Since the universe began 13.8 billion years ago, some believe it to be 13.8 billion light-years in diameter. The brightness of the stars beyond it may not have reached here. But today scientists estimate that its actual diameter is 93 billion light years. Using the bayesian model, the actual universe is thought to be 250 times larger than the visible universe.