> a globe is a model of the earth You can't put a globe in your pocket. A big, round globe is too bulky to carry from place to place. That's why there are maps. Travelers can easily fold paper...
The big, blue marble
The earth looks like a big, blue marble to astronauts flying in outer space. It's easy for them to see the round shape of the earth because the astronauts are so far away. But how can you see the...
Sky “fireworks”
People who live far enough north or far enough south are often treated to a giant "fireworks" display on clear nights. Great sheets of light seem to hang in the sky, rippling and wavering like...
Waves from space
Right this minute you're being hit by "bullets" from outer space! Space is full of waves. These aren't the kind of waves you see on an ocean, of course. They are waves of radiation. Radiation is...
“Shooting stars”
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 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...