The Milky Way

The galaxy we live in

You can see it with your eyes

The numbers

We see it from inside: it is like understanding the shape of a forest while standing among the trees.

The milky band in the sky is not a cloud: it is the disk of the galaxy seen edge-on.

These are not in the book: there was no room on paper.

At its center there is a supermassive black hole, whose existence was confirmed in 2022.
That black hole is called Sagittarius A star, and it is a very strong source of radio waves.
Almost every galaxy is thought to have a similar object at its center.
From cities the Milky Way can no longer be seen: you need a truly dark sky to catch it.
For centuries people argued about whether that band was a cloud or a crowd of stars.

The first question is the one printed under the QR code, with the answer the book did not give. The other four only exist here.

Question 1 of 5★ is the one from your book

What is the Milky Way?

Question 2 of 5

Why was its shape hard to understand?

Question 3 of 5

What is the pale band in the sky?

Question 4 of 5

What is at the center of the Milky Way?

Question 5 of 5

Do other galaxies have a black hole at their center?

I look like a pale cloud stretched across the sky, but if you look at me through binoculars I crumble into thousands of separate dots. What am I?

At my center I hide something that no light comes out of, and for years you only suspected it because it made a lot of radio noise. What am I?

Activity 1

Point any binoculars at it: what looked like a cloud breaks into thousands of separate stars. It is the experiment Galileo did.

Activity 2

Try looking at it from the city and then from the countryside in the same week: the difference you see is all light pollution.