Rocky planet

Dun-colored (rocks)

Diameter: 3,00 miles

Rotation: 59 Days

Orbit: 88 days

Temperature Average: 590-725 K, sunward side

Moons: None

Number from Sun: 1

Distance from the sun: 36 million miles

Atmosphere: none

Mercury is the closest planet to the sun. It is a bright orange-yellow color. It's hard to see from Earth because of its size and where it is. Mercury is very small, and because it's so close to the Sun, we often lose sight of it.

Mercury is named after a Roman god who flew very fast. A famous astronomer named Copernicus figured out that Mercury's year is equal to 88 days on earth. It has the shortest year of all of the planets. Even with telescopes, it is difficult to see Mercury. We have learned a lot about this planet by using radar. We found out that one day on Mercury is equal to 59 earth days.

In 1973, a space probe named Mariner 10 left to study Venus and Mercury. The probe took thousands of pictures and measurements of the planet. We found that it has a lot of craters on its surface, and that it would fit inside Earth almost ten times. Its diameter (how big around it is) is just 3,031 miles.

Mercury's gravity is not very strong. If you were on Mercury, you could jump very high and throw a ball really far. Mercury does not have oxygen that the earth has, so we could not breathe there without a spacesuit. The temperatures are very hot, about 800 degrees Fahrenheit! Mercury also does not have any water. It is a lot like Earth's moon. Mercury does not have any moons. Since it has no air, the sky is black even during the day time, and you can see stars on Mercury all the time.

Think about it:  What usually causes craters? How big can craters be? Are there any craters on Earth?

To learn more about Mercury, visit this site:  http://www.worldalmanacforkids.com/explore/space/mercury.html