Earth



CONDITIONS:

The conditions on Earth vary from place to place and season to season. It can be hot or cold, sunny, rainy, snowy, or windy.

Earth is a terrestrial planet. It has a core, a rocky mantel, and a crust. About 75% of the Earth is covered in water, giving the Earth its nickname, "the blue planet."

DID YOU KNOW?


 * People once believed that Earth was the center of the solar system. Now we know that the Sun is the center.
 * Earth is the only planet in the solar system known to have life.
 * Earth is "just right" for life because it is not too cold, not too hot, and because it has an atmosphere and lots of liquid water.
 * All the continents on Earth used to be one big continent, but they have broken apart over many millions of years.
 * The Earth's weight is estimated at 6,580,000,000,000,000,000,000 tons!

WE STILL WONDER...


 * How does the Earth move?
 * How old is the Earth?
 * Why is Earth the only planet with life?

SOURCES

Astronomy for Kidsl: [|Earth] BrainPop, Jr.: [|Earth] NASA [|Earth Facts & Figures]

Berger, Melvin, A Tour of the Planets, 1994. Davis, Kenneth C., Don't Know Much About the Solar System, 2001. Orme, Helen and David, Let's Explore Earth, 2007. Vogt, Gregory L., Earth, 2000.