What is the Milky Way?

Your question of the month in April (2016)
Sophie, 8 years old

Have you ever heard of the "Milky Way" and asked yourself what it might be? We will explain to you what it is all about.

When the sky is clear at night and the stars are clearly visible, you can sometimes find the Milky Way: It looks like a long, milky ribbon, stretching across the sky. Since it looks so cloudy and "milky", it was named the Milky Way.

But what exactly is the Milky Way? It is an accumulation of one hundred billion stars. Since they are very, very far away from us, we only see them as a dim light, which for us looks like that milky ribbon - the Milky Way. The sun and our earth are also part of the Milky Way. It is our "galaxy". Galaxies are accumulations of stars, planets, gas and dust. There are many more galaxies in space besides the Milky Way, such as the Andromeda Galaxy, one of our "neighbouring" galaxies.
By the way, the Milky Way is also called Galaxis. "Galaxis" is Greek and more or less means "milk".

The diameter of the Milky Way is approximately 100,000 light years and it is between 3,000 and 16,000 light years in width. Do you know what a light year is? In space, the distances are almost unimaginably large. The distance from the earth to the sun is just peanuts! That's why distances in space are stated in light years instead of kilometres. A light year is the distance light travels within a year. If the Milky Way has a diameter of 100,000 light years, it means that light would take about 100,000 years to cross the Milky Way. An unbelievably long time!

It is hardly possible to see the innumerable amount of stars, which form the Milky Way, with the naked eye. But if you look through a telescope, you will be able to distinguish individual stars. This works best if the sky is clear and if you are surrounded by as little light as possible.