Surface of Mars

The surface of Mars is dry and dusty. The highlands of the southern hemisphere have more craters than the lower areas in the northern hemisphere. One of the craters is the huge Hellas Planitia. It is about half the size of the continental United States.
There is an area on Mars called the Tharsis Bulge which has four huge volcanoes. These volcanoes have not erupted for millions of years. The largest volcano is called Olympus Mons. It is 27 km tall, making it the highest mountain in the Solar System, much higher than Mount Everest on Earth. It is 625 km across and takes up an area as big as the US state of Arizona. Mars also has a huge canyon called the Valles Marineris. It is much bigger than the Grand Canyon on Earth. It is 4000 km long, up to 7 km deep and up to 200 km wide. Scientists think that when the Tharsis Bulge was created, the surface of Mars cracked to form the Valles Marineris.
Like the Earth, Mars has ice caps at its poles. They are made from ice and frozen carbon dixoide. During the Martian winter, the southern cap grows as carbon dioxide from the atmosphere freezes.
In some places, there are channels that look like they were made by running water. So, a long time ago Mars may have had lakes and streams made of water.
There is an atmosphere on Mars, but it is very thin. There is also much more carbon dioxide in it than oxygen. (Oxygen is the gas we want when we breathe in, carbon dixoide the gas we get rid of when we breathe out.) So, we would need spacesuits to visit Mars.