Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury.
In English, Mars carries the name of the Roman god of war and is often referred to as the “Red Planet“ because the iron oxide prevalent on its surface gives it a reddish appearance that is distinctive among the astronomical bodies visible to the naked eye.
Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys, deserts, and polar ice caps of Earth.
Internal structure
- Like Earth, Mars has differentiated into a dense metallic core overlaid by less dense materials.
- This iron(II) sulfide core is thought to be twice as rich in lighter elements as Earth’s.
- The core is surrounded by a silicate mantle that formed many of the tectonic and volcanic features on the planet.
- Elements in the Martian crust are iron, magnesium, aluminum, calcium, and potassium.
- The average thickness of the planet’s crust is about 50 km (31 mi).
- Earth’s crust averages 40 km (25 mi).
