Mars is the forth planet from the Sun at about 140 million miles away.
It is often known as “The Red Planet” because of its distinctive red colour when seen with the just unaided eye and expecially, through a modest telescope.
It is in many ways quite similar to the Earth.
Mars is about the same size as Earth and is the closest planet to the Earth, although further away from the Sun.
Mars also has a similar length day, as it rotates about its axis every 24 hours, just like Earth. It also has similar season variations, as the Mars axis is inclined at 24 degrees to the orbit, which is very similar to Earth.
The Martian year is nearly twice as long as the Earth year, because Mars takes 687 Earth days to go once around the Sun.
A number of space missions have looked at Mars and some have landed on the surface.
It has been found to have a rocky surface, with the red colour resulting from iron oxide prescence.
There are many surface features including mountains, volcanoes, craters and valleys. Mars has a huge volcano called Olympus Mons, which at 15 miles high, is much larger than any mountain on Earth, or any known elsewhere in the solar system.
The atmosphere is over 95% carbon dioxide and the temperature is fairly cold. Winter temperatures probably go down to colder than -100 degrees Centigrade.
For decades it was suspected that there might be some forms of life on Mars, but none has been found as yet. And the atmosphere and low temperatures do not seem very hospitable to life as we know it.
There is evidence however, that some of the surface features might have been created by water flows long ago. And recently, evidence of water ice was detected at a pole.
Mars has two small moons called Phobos and Deimos.
