We sec the sun every day. If it is (sun), we can see the moon at night, too. The moon is near us. So far astronauts (visit) the moon several times. The moon is almost nearest satellite (卫星)to the earth in space.
Light (travel) at 300, 000 kilometers a second. Light reaches us from the moon in less than a second and a half. The moon is about 382, 000 kilometers away.
Light from the sun arrives in the earth in about 8.5 (minute). The sun is about149, 640, 000 kilometers away the earth. Other stars are much (far) away than the sun. Light from the nearest star reaches (we) in about four years. When you look at a star, it is very small. in fact many of them are much bigger than the sun. They look small only because they are (real) far away.
