The Martian Atmosphere

The thin atmosphere of Mars is mainly made up of carbon dioxide, nitrogen and argon gases. Mars is also frequently impacted by rogue objects from space like meteorites, asteroids and comets. The temperature on Mars can go from as high as 20 degrees Celsius to as low as -153 degree Celsius. The heat from the Sun escapes the Red Planet quite easily, and this difference in temperature can be experienced if you were on Mars. If you were to be standing on Mars' surface at noon on the equator, it would feel like spring at your feet (24 degrees Celsius) and winter at your head (0 degrees Celsius). Occasionally, Mars witnesses strong winds causing storms of dust which could potentially cover the entire planet for months.

Size and distance

Mars is only about half the size of Earth with a radius of 3,390 km. Mars is 1.5 astronomical units away from the Sun from an average distance of 228 million kilometres. One astronomical unit ( abbreviated as AU) is the distance between the Earth and the Sun.

Structure

At its centre, Mars has a dense core between 1,500 and 2,100 km in radius. It is made mostly of iron, nickel, and sulphur. The core is surrounded by a rocky mantle between 1,240 and 1,880 km thick and above that a crust made of iron, magnesium, aluminium, calcium and potassium. This crust is somewhere between 10 and 50 km deep.

Surface

Though Mars appears red, the surface of the planet is composed of several colours including gold, brown, and tan. The reason Mars appears reddish is due to iron oxidation — or rusting — in the rocks, regolith (Martian "soil"), and Mars dust. This dust gets swept up into the atmosphere and makes the planet look mostly red from a distance.

Moons

Mars has two small moons, Phobos and Deimos, that may be captured asteroids. They’re potato-shaped because they have too little mass for gravity to make them spherical. The moons get their names from the horses that pulled the chariot of the Greek god of war, Ares. In ancient Greek, Phobos means “flight,” and Deimos means “fear.”