A big lump of rock and metal---a meteoroid---rushes through the blackness of space. For billions of years, ever since the planets were formed, it has been zipping around and around the sun. But now...
The tiny planets
Just as there are giant planets in the sun's family---Jupiter and Saturn---there are also "dwarf" planets. These small planets are called asteroids. Asteroids circle the sun in a ring between Mars...
The faraway worlds
> Space probes have visited Uranus and Neptune. Someday, we may send a > space vehicle to Pluto, the farthest planet. The seventh, eighth, and ninth planets of the sun's family are very far away....
A many-ringed planet
The sixth planet from the sun is Saturn. It is the second largest planet---nearly ten times bigger than the earth. Saturn is named after the Roman god of farming. It has a rocky center, probably...
The giant planet
The giant of the sun's family is the planet Jupiter. It's the biggest planet of the solar system---more than eleven times bigger than the earth. Jupiter is named after the king of the Roman gods. ...
The red planet
At night, you can sometimes see a bright "star" that shines with a reddish gleam. It is Mars, the "red planet," named after the Roman god of war. Mars is the fourth planet from the sun ---about 142...
Earth’s “twin”
The second closest planet to the sun is Venus. Seen from the earth, it is the brightest of all the stars and planets in our sky. Sometimes it can even be seen in daylight. Because of its beauty, it...
Closest to the sun
The planet closest to the sun is Mercury. It is one of the smallest of the nine planets---only a little more than one-third the size of the earth. Seen from the earth, Mercury appears, disappears,...
The sun’s family
The planet earth is part of a family. It is one of nine planets that belong to the sun. We can see some of these planets at night, shining like bright stars. Like the earth and the moon, the other...
On the moon
People have visited the moon and walked on it, so we know what the surface of the moon is like. This big ball of gray rock has broad, flat plains covered with powdery rock dust. There are rugged...
