How Big is the Universe?

The human mind can not imagine a true picture of the universe. Not only we do not know exactly how much but it is hard for us to imagine its size.

If we start from our planet, and little-centric, you will immediately see why this is so. Earth is part of the solar system, but its quite a small part. Solar System consists of the Sun, the planets revolve around it, small planets and meteors. Solar system is just a glimpse of one another, much larger system, called galaxy. It is composed of billions of stars, some of which are much larger than the Sun, and may have their own systems like solar.

The stars we see in our galaxy (the Milky Way) are the real suns. They are so far away from us, that distance is not measured by miles, but by light years. Light travels at a speed of 300,000 miles a second, and a year spent about 9 600 000 000 000 (nearly ten trillion) miles.

Nearest bright star to the earth is Alpha Centauri. Do you know how far away from us? 40 billion miles! But we are talking about galaxy. It is thought to be widespread around 100 000 light years. And our galaxy is only a small part of a much bigger system.

In addition to our own Milky Way there are probably millions of other galaxies, and the nearest to us is about 2 million light years away. And maybe they all galaxies together make up only part of a much bigger system!

Now you understand why we can not imagine the size of the universe?