10.1

A planetarium is like a cinema. A projector shows a picture of the night sky on a big ceiling

above you. There isn't much light in the room, but there are a lot of small lights on the

ceiling. These lights look like stars, planets and galaxies. It looks so real. You think

you're outdoors. In a planetarium you can see how the Earth and other planets orbit the

Sun. Eight planets go around the Sun and the Earth is one of them. There are a lot of galaxies

in the universe. A galaxy is full of stars. There are so many stars in a galaxy that it

looks like a cloud. The name of our galaxy is the Milky Way. Our galaxy is so big that

it takes the Sun 220 million years to go around it.