Page:Illustrated Astronomy.pdf/36

 Review questions

1 · Why does the Sun shine?

2 · What makes the stars different from one another?

3 · How is the Sun inside and how do we know that?

4 · How is energy transferred from the Sun to Earth?

5 · Which layer of the Sun is visible during an eclipse?

DID YOU KNOW THAT…

...the Sun contains 99,9 % of the Solar System’s mass?

In other words, if we gather all the planets and their moons, and asteroids, and comets, they become just a thousandth part of the Solar mass.

DID YOU KNOW THAT…

''...the Solar System travels to 220 km/s around the Milky Way’s center and, besides its high speed, it takes 220 million years to orbit once around the Galaxy? This period is called a galactic year or cosmic year.'' 36 • • •