|Diameter||6794 km, 0.53 x Earth's|
|Average Distance from Sun||228 x 106km = 1.523 AU|
|Atmosphere||Very thin carbon dioxide|
|Length of Day||1.02 days|
|Length of Year||687 days|
|No. of Moons||Two|
|Gravity||0.38 x Earth's|
Mars is the fourth planet from the Sun. It is the most likely place in the Solar System to find alien life. If life is found there it won't be little green men, but very tiny bacteria.
Today Mars is very cold and only has a tiny amount of water, but scientists think that it was much warmer and wetter in the past. There is no flowing water on the surface in rivers or lakes. All of the water is trapped underground in rocks or in the ice caps at the north and south poles. The NASA spacecraft Pathfinder which landed on Mars also took pictures of a thin icy dew in the mornings.
Mars has seasons like Earth, but because the year is twice as long, the seasons also last twice as long.
The surface of Mars is rocky, with craters and huge canyons across it. It is called the Red Planet because of the colour of the dust. This is an orangey-red colour because it contains a lot of oxidised iron (rust).
Some of the canyons were that we see on the surface were created by water that flowed across the planet thousands of years ago, and some were formed by the surface cracking. The largest is called Vallis Marineris, which stretches for about 4000km, or about the same distance as the width of the United States. It is so deep that if you dropped Mount Everest inside it, the mountain would just peek above the top. There are also ice caps at both the North and South poles, made of water ice and carbon dioxide ice. These grow in the winter as it gets colder and shrink in the summer as it gets warmer and the ice melts.
|All Rights Reserved Beagle 2|
Authors: Carolyn Brinkworth and Claire Thomas
Last updated: July 2001