The size of Mars is approximately half of the size of Earth. Its density is lower than the density of Earth, because it is only 15% of the terrestrial. It has also 11% of weight of Earth. The surface of Mars is only a bit smaller than the dry surface of Earth. While Mars is larger and more massive than Mercury, Mercury has a higher density. This results in a slightly stronger gravitational force at Mercury’s surface. It is because the gravitational force acting on Mercury is far more strong than is the gravitational force acting on Mars.
The red-orange appearance of the Martian surface is caused by iron(III) oxide, more commonly known as hematite, or rust. Mars is the fourth planet from the Sun in the Solar System. It is very often referred to as the “Red Planet” because of its reddish appearance.
Mars is terrestrial type of planet, which has also the atmosphere very similar to ours. However it is more thin. The surface of Mars is similar to surface of Earth’s Moon, especially because of structure of various impact craters caused by meteorites. Martian surface is more similar to the Earth’s surface, because of very similar valleys, mountains, canyons, deserts, flat plains and with white polar caps.
Mars is now a geologically inactive planet with no known tectonic activity. It is the site of Olympus Mons, the highest known mountain in the Solar System, and of Valles Marineris, the largest canyon. Olympus Mons means in translation something like “home of gods”.
How does the night sky look on Mars?
With the existence of various orbiters, landers, and rovers, it is now possible to study astronomy from the Martian skies. While Mars’ moon Phobos appears about one third the angular diameter of the full Moon as it appears from Earth, Deimos appears more or less star-like, and appears only slightly brighter than Venus does from Earth.
There are also various phenomena well-known on Earth that have now been observed on Mars, such as meteors and auroras.
Sunset seen on Mars: