4 MEET MARS THE RED PLANET Mars is one of the planets that orbit or travel around the sun in the solar system It is the fourth planet from the sun It is also Earth’s outer neighbor Mars is close enough that we can see it from Earth without using a telescope Mars is called the red planet because its surface is red Sometimes it even looks like a red star in the night sky from Earth In this photograph of Mars the white areas are clouds surrounding volcanoes
5 The solar system is the sun and all of the planets dwarf planets moons asteroids comets and small icy bodies that orbit the sun VOCABULARY Mars is about 142 million miles 228 million kilometers away from the sun It has two small rocky moons called Phobos and Deimos For centuries people have wondered whether there is life on Mars So far scientists have found no obvious signs of life on the planet However they are still trying to find out if life forms may have ever existed on Mars Scientists are also studying whether there was ever water on Mars From Mars Earth and our moon look like stars This photo was taken from Mars in 2014
6 HOW BIG IS MARS Mars is the second smallest planet in the solar system Mercury is the only planet that is smaller The diam eter of Mars or the distance through its center is about 4,224 miles 6,800 kilometers That is about half the size of Earth’s diameter This illustration shows the relative sizes of the planets in our solar system Earth is the third from the the sun left Mars is the fourth
7 THINK ABOUT IT Mars is smaller than Earth But Earth and Mars have about the same amount of dry land How can that be Mars is tiny if you compare it to the largest planet in the solar system which is Jupiter Jupiter has a diameter of about 89,000 miles 143,000 kilometers That is about twenty-one times larger than Mars In fact Jupiter is two and a half times larger than all the other planets in the solar system put together The storm on Jupiter known as the Great Red Spot center right is 10,250 miles 16,496 kilometers across or more than twice the diameter of Mars
