Earth

Earth is the third planet outward from the sun in the solar system. It is about 93 million miles away from the sun. It is very different from the other seven planets in our solar system. As far as we know, it is the only planet with air we can breathe. It is the only planet with plants and animals. It is the only planet with liquid water. In fact, Earth's surface is almost three-fourths water. It is not too hot and not too cold. The average temperature is about 59 degrees. It is just right for us to live on.

Earth has air we can breathe. Our air is a mixture of gases that surround Earth. It is kept in place by the pull of Earth's gravity. If Earth were a much smaller planet like Mercury, its gravity would be too weak to hold the air around Earth. The air around Earth, including the ozone layer, protects us from harmful rays from the sun.

From space, Earth is a very .....