A ball, far away

About this video

Look up on a clear day and the Sun seems simple: a small, bright, flat circle crossing the sky. This video looks at what it really is.

First, what it does for us. The Sun gives us light: when it is up, it is day, and everything around us is bright. It also gives us heat. Stand in the sunshine and you feel warm; step into the shade of a tree and you feel cooler. Almost all the light and warmth on the Earth comes from the Sun.

Next, its shape. In the sky the Sun looks like a circle, but it isn't a flat disc. Turn a flat disc and it soon becomes a thin line; a ball looks round from every side. The Sun is a ball, like an orange: a giant ball of very hot, glowing gas.

Then, its size. The Sun looks small only because it is very, very far from us. Anything looks smaller the farther away it is, like a ball rolling away down a long road. Up close the Sun would be enormous. Drawn to the same scale, the Earth next to it is just a dot: about 109 Earths side by side would stretch across the Sun.

Finally, a warning that goes with all of this: never look straight at the Sun, not even for a moment, and never through binoculars or a telescope. Its light can damage your eyes for good.

The big idea: the Sun is a huge, hot, glowing ball, very far away, and it gives us light and heat.

Transcript

1. 0:00The Sun. In the sky it looks like a small, flat circle.
2. 0:07But what is it, really?
3. 0:18First, it gives us light. When it is up, it is day.
4. 0:24And it gives us heat. Stand in the sunshine and you feel warm.
5. 0:30Step into the shade, and you feel cooler.
6. 0:34Almost all the light and warmth on the Earth comes from the Sun.
7. 0:40It looks like a circle. But turn a flat disc, and it becomes a thin line.
8. 0:48A ball looks round from every side. The Sun is a ball.
9. 0:54A giant ball of very hot, glowing gas.
10. 1:04So why does it look so small?
11. 1:07The farther away something is, the smaller it looks.
12. 1:16And the Sun is very, very far from us.
13. 1:30Up close, it would be enormous.
14. 1:35Next to it, at the same scale, the Earth is a tiny dot.
15. 1:52One thing to remember. Never look straight at the Sun.
16. 1:57Not even for a moment, and never through binoculars or a telescope.
17. 2:03Its light can damage your eyes for good.
18. 2:08The Sun is a huge, hot, glowing ball, very far away. It gives us light and heat.