Mars

Mars is the fourth planet from the Sun. People call it the Red Planet. This is because it looks orange-red in the sky.

Mars is a rocky desert planet. It has a very thin air around it. The air is made mostly of a gas called carbon dioxide. The weather on Mars is super cold. It gets as cold as minus 153 degrees. Sometimes it warms up to 20 degrees, but not often. Mars also gets hit by dangerous rays from space. There is some water on Mars. You can find it frozen in the ground. There are also thin clouds and frost. The polar regions have big caps of ice and frozen gas. But Mars has no oceans or lakes with liquid water. If you stood on Mars, you would feel lighter. You would weigh about one third of what you weigh on Earth. Mars is about half as wide as Earth. But it has about as much dry land as all of Earth combined.

Mars has lots of fine dust everywhere. Even the weak winds can blow this dust around because Mars's gravity is so weak. The planet has two very different sides. The north side is mostly flat and smooth. The south side is bumpy with many craters. Mars shakes sometimes from earthquakes underground. It also has giant volcanoes that are no longer active. The tallest volcano is as tall as three Mount Everests stacked on top of each other. Mars has one of the biggest canyons in our whole solar system. It is longer than the entire United States. Mars has two tiny moons that look like potatoes.

Mars tilts just like Earth does, so it has seasons too. One year on Mars takes almost two Earth years. One day on Mars is almost the same as an Earth day. Long ago, Mars might have had oceans and life. Scientists are still looking for clues about this. People have been watching Mars in the night sky for thousands of years. The first spacecraft flew toward Mars in 1963. The first successful visit was in 1965. Since 1997, there have always been spacecraft exploring Mars. Scientists think Mars might be a good place for people to visit someday.