Mars

Mars

Someday people will stand on the surface of another planet. That planet will probably be Mars. Maybe you’ll be one of the people to go!

Mars is one of the brightest objects in the night sky. It looks like a reddish star. The ancient Romans named Mars after their god of war because it was the color of blood. The red planet is the next planet out from the Sun after Earth. Of all the planets in the solar system, Mars is the most like Earth.

WHAT IS MARS LIKE?

Mars is a small, rocky planet much like Earth. Pictures of the surface of Mars sent back by spacecraft look like deserts on Earth.

Mars is about half the size of Earth, but its land area is about equal to Earth’s land area. That’s because Mars has no oceans. Mars does have water, however. Some of the water is frozen in icecaps at the planet’s north and south poles. Scientists also think there may be a lot of water frozen underground.

A day on Mars is just a bit longer than a day on Earth. Mars even has seasons! Although Mars is much colder than Earth, on the warmest summer days it gets up to about 60° Fahrenheit (15° Celsius). That would be a very pleasant day on Earth.

STANDING ON MARS

Rocks and red, dusty soil cover the Martian surface. You feel light—you can jump higher and throw a ball farther than you can on Earth. Gravity, the force that holds you to the ground, is weaker on Mars than it is on Earth.

There’s a pinkish sky overhead, perhaps with a wisp of cloud. At night you see two tiny moons above you. The moons are named Phobos and Deimos. There might be a breeze blowing, but you cannot breathe the air. The air on Mars is very thin. It does not have much oxygen, the gas you need to breathe.

GIANT-SIZED LANDSCAPE

Mars may be a small planet, but many of its natural features are bigger than similar features on Earth. That’s because the weaker gravity on Mars doesn’t make huge mountains collapse or pull steep canyon walls down. The red planet has enormous volcanoes. The biggest volcano in the solar system, Olympus Mons, is on Mars. It is 16 miles (26 kilometers) high. That’s more than twice as high as Mount Everest, the tallest mountain on Earth! The base of Olympus Mons would cover the state of Arizona.

Mars also has enormous canyons. Valles Marineris, a group of connected canyons, would stretch from New York State to California on Earth! Valles Marineris is more than 4 miles (7 kilometers) deep in places. The Grand Canyon is just a ditch compared to that!

There are also enormous channels on Mars that look like dried up riverbeds. Scientists think that Mars once had lakes and rivers. They think that once there were big floods on Mars. The floods carved the channels. Mars is very dry today, however. Scientists are trying to figure out what happened to the water.

Mars has dust storms that sometimes engulf the entire planet. The giant storms can blow for months. The planet’s lower gravity allows the dust to float up in the air for a long time. The dust makes the sky pink.

HOW DO WE LEARN ABOUT MARS?

Scientists called astronomers look at Mars through telescopes. The best pictures of Mars come from the Hubble Space Telescope. This telescope orbits in space high above Earth.

Several countries have sent spacecraft to visit Mars. Some of these spacecraft landed on the red planet. In 2004, the United States landed a pair of robot rovers named Spirit and Opportunity on Mars. Rovers have wheels. They can roll around and look at rocks. They send pictures and other information back to Earth. Spirit and Opportunity found strong evidence that Mars once had liquid water.

IS THERE LIFE ON MARS?

So far, scientists have not found anything alive on Mars. They think that the surface of Mars is too cold and poisonous for life. They wonder if there is life underground. Perhaps Martian life forms live in cracks in the rocks.

Scientists also wonder if there was life on Mars in the past. Mars was once warm enough to have liquid water in lakes and rivers. Living things need water.

Mars is cold now because its air is so thin. Earth is warm enough for life because its air traps heat from the Sun. Scientists wonder if the air around Mars was once thick enough to trap heat from the Sun.

COULD PEOPLE LIVE ON MARS?

If people ever live on other planets, Mars will probably be the first one they move to. Some scientists and government officials want to send astronauts to Mars.

Other scientists and officials do not think that sending people to Mars is a good idea yet. They think it is best to keep exploring the red planet with better robot rovers.