Mars is the fourth planet in the Solar system by distance from the star. The diameter of the planet is 6794 km (0.53 of the diameter of the Earth).

Its orbit is 1.52 au from the Sun. Mars has two moons: Phobos and Deimos. The period of rotation of the planet around the axis is 24 hours 37 minutes, the period of rotation around the Sun is 1.88 Earth years.

The atmosphere of Mars is sparse and 95% consists of carbon dioxide, it also contains nitrogen, argon and oxygen. The surface of the planet is covered with craters, volcanoes and canyons. It is assumed that in the distant past Mars could have been covered with water. For unexplained reasons, whether due to the absence of a magnetic field, or due to a geological catastrophe (for example, the fall of a very large asteroid or even a planetesimal), the planet lost its magnetic field, and due to the solar wind soon lost both the oceans and most of the atmosphere. Thanks to the spacecraft, evidence of the existence of water ice in the Martian soil was obtained. The temperature on the planet's surface ranges from -150 ° C to +20 °C.

It is the seventh largest among the planets of the Solar system, clearly visible from Earth with the naked eye. Mars is one of the most studied planets by man. The first close-up images of the planet were obtained in 1965. To date, both orbital stations have participated in the study of Mars (Viking, Mariner — USA, Mars — USSR programs/Russia), as well as landers and rovers (Opportunity, Curiosity — USA). In 2016, the international ExoMars mission began its work. The Misssia lander — Schiaparelli — crashed during landing, falling to the surface of the planet at a speed of up to 300 km/h.