Mars is called the the red planet because stuff called iron oxide on the surface makes it appear red.
Mars is the 4th planet from the Sun.
It is 228 million kilometres from the Sun.
It takes the planet 687 days to orbit the Sun.
Mars has 2 moons.
Spacecraft from Earth have landed on Mars.
What is it like on Mars?
The surface is a cold desert. There are volcanoes, mountains, valleys, and vast plains. The largest mountain and volcano in the solar system is on Mars. It is called Olympus Mons and is 24 kilometres tall.
Mars is smaller than Earth but it has about the same land area as Earth because there are no oceans on Mars.
Mars has a core of iron in the middle, and a thick crust on the outside. The atmosphere on the planet is mainly carbon dioxide with very small amounts of other gases, such as nitrogen and oxygen.
The planet is named after the Roman god of war
Exploration of Mars
Russian and American space craft have been sent to investigate Mars beginning in the 1960's. There are currently two scientific robots exploring the surface, and five orbiters surveying the planet. They have found evidence of volcanoes that erupted under the ice sheet billions of years ago.
Water on Mars
In summer months on Mars, scientists believe that liquid water runs down canyons and crater walls. Long, dark stains, hundreds of metres long are left on the Martian landscape, showing where the water has run downhill in the warmer months.
These stains are seen in images taken from a NASA Mars exploration orbiter that travels around the planet taking pictures.
Scientists are unsure where the water comes from, but it may rise up from melting ice far underground.
Finding water is important to scientists who believe that where there is water, there may be some living organisms.