The Inner Planets The inner planets are all

The Inner Planets

The inner planets are all the planets that are inside the asteroid belt. These are Mercury, Venus, Earth, and Mars.

They are called the terrestrial planets because they all have rocky surfaces. The word terrestrial comes from the Latin word terra, which means “rock”.

Mercury • Mercury is the closest planet to the Sun. • It has the fastest orbit of any of the planet, finishing in just 88 days. • Mercury is about the same size as our moon, and like our moon, is covered in craters. • It has no moons! • One day on Mercury is about 58. 5 Earth days.

• The name “Mercury” comes from the Roman messenger god. He was a god with wings on his shoes, and he flew very fast. Because the planet Mercury has the fastest orbit, scientists named it after this Roman god.

• Because Mercury is such a small planet, it has almost no gravity. That means that the planet can’t hold air and gas to make an atmosphere. Also, solar winds from the nearby sun blow away the air. Mercury has almost no air!

Venus • Venus is the second planet from the sun. • A day on Venus takes longer than a year!! • Venus is very similar to Earth in many ways: they have similar gravity, they are made of the same materials, and they are about the same size. • There are no moons.

• Venus gets its name from the Roman goddess (female god) of love and beauty. People named the planet after her because they thought the colors and clouds on Venus looked beautiful.

• It is extremely hot on Venus. It is even hotter than Mercury. This is because of something called the greenhouse effect. • Venus is covered in clouds, and it traps the hot air close to the planet so it has nowhere to go, so it just gets hotter and hotter. • Venus is very cloudy, but it is just too hot to rain.

Earth • It is the third planet from the Sun • It has one moon. • One day on Earth is 24 hours; one year is 365 days. • Earth is the only planet we know that has life. • Earth is the biggest of all the inner planets.

• Earth is the only planet not named after a Roman god. • Earth is a word that means “ground, ” “dirt, ” or “soil. ” • When Earth got its name, people didn’t know it was 70% covered in water, or they probably would have called it Oceania.

• Earth is the densest planet in the solar system. That means that it has the most stuff in the smallest space. For example, pretend you have two loaves of bread the same size. If you squeeze one into a small ball, one is bigger and one is smaller. They are still the same amount of bread, but the smaller one is more dense.

Mars • Mars is the fourth planet from the sun, and the last of the inner planets. • Mars is about half the size of Earth. • It has two moons, named Phobos and Deimos. • It is called “The Red Planet” because of its red color, which comes from iron in the ground. • The name Mars comes from the Roman god of war.

• Scientists believe that there once were lakes, rivers, and even oceans on Mars, because of what the land looks like now. • Now the only water on Mars is found frozen in the polar ice caps.

• The largest volcano in the Solar System is on Mars. • It is called Olympus Mons, and it is 26 km high. It is 500 km across, and has cliffs over 6 km high all around it. • It’s over 3 x the size of Mt. Everest!

The End!