Scale of the universe

The Earth is big. It has a radius 6371 km long (3900 miles) and holds over 7B people. But it is nothing compared to the universe.

Space is so big, that using km or miles to calculate distances is completely useless. In our solar system we can use the Astronomical Unit (au) which represents the average distance from Earth to Sun: 150.000.000 km or 92.955.800 miles.

When we are talking about distances outside our solar system, we have another measurement, light-year which represents the distance which the light travels in a year: 9461 x 10^12 km ~ 9 trillion km or 5879 x 10^12 miles ~ 6 trillion miles.

For example Jupiter is 4,20 au away form Earth, but Neptune is 30 au far from Earth. The distance from Earth to the second nearest star, Alpha Centauri, is 4367 ly away. Or the nearest galaxy, Andromeda, is 2537 million ly away from Earth. But again, this is nothing compared to the whole universe!

We also have larger measurements units, like parsec which is 3,26 ly.

We have also megaparsec which is one million parsecs, or the biggest measurement unit of all times, a gigaparsec is one billion parsecs long!

To get a closer look on how big the universe actually is, take a look at the following proportions:

If the Sun, which covers 99.8% of our solar system, would be the size of an atom, the whole galaxy would be the same size as Russia!

If the Solar System would be a mm long, the Observable Universe (93 billion ly/28 billion parsecs) would be the same size as Saturn!

Let me say that Earth is also very small compared to other celestial bodies. Comparing Earth with Jupiter is the same to compare a bean to a football ball. If you compare Earth to the Sun is the same if you compare a small seed to a orange. This is just the beginning.

If you would travel with the speed of light (300000 km/h) around a massive star in constellation Canins Major, it would take 8 years to make just 1 round.

In the constellation Coma Berenices, astronomers found a black hole 12 times bigger then our solar system.

We are so small, but that doesn’t mean we are not important. Every little thing you do can make a difference here, on Earth.

Hope this article was helpful for you, to really understand the meaning of the universe. If you learned something new, share this post to your friends! That was all for today, see you next time on Space Learning Web!