Mars, also called the Red Planet, has been fascinating mankind since prehistoric times. Its name originated in Greece (Greek: Ares) and means “God of War”, probably because of its red color. Mars has always been one of the favorite sources of various speculations and science-fiction stories. Its secrets and mysteries seem to endlessly feed mankind’s imagination and curiosity, thus turning the red planet into a source of infinite dreams and hopes.
Although Mars is the next most favorable place for human inhabitation (after the Earth) in our solar system, it is in some important aspects significantly different from our blue planet. Due to Mars’ elliptical orbit, there is a temperature variation of about 30°C (86 F) at the subsolar point between aphelion (point farthest from the sun in a given orbit) and perihelion (point nearst from the sun). This temperature variation influences Mars’ climate extremely. For instance, while the average temperature on Mars is about 218 K (-55°C, -67 F), Martian surface temperatures varies from 140 K (-133° C, -207 F) in winter to almost 300 K (27° C, 80 F) during summer.
Futhermore, Mars has a very thin atmosphere, which leads to very low pressures. The average pressure on the surface of Mars is only about 7 millibars and this is less than 1% of the values measured on Earth!
Mars’ atmosphere is absolutely human-hostile then it consists mostly of a very small amount of remaining carbon dioxide (95.3% – this explains the red color), nitrogen (2.7%), argon (1.6%) and traces of oxygen (0.15%) and water (0.03%). Now, to complete the “horror-scenery” there are even sometimes very strong winds and vast dust storms on Mars that on occasion engulf the entire planet for months!