We explain what Mars is, its location in the solar system and its dimensions. Also, what are its characteristics, its climate and geological composition.
What is Mars?
Mars is a planet solar systemthe fourth farthest from the Sun and the smallest after Mercury. It is one of the inner planets (those between the Sun and the Asteroid Belt), along with Mercury, Venus and Earth. It is the only reddish planet that can be seen in the night sky.
Due to the interest it has always aroused in human beings and its relative proximity to Earth, Mars has been the object of numerous space missions. In recent decades, unmanned missions and robotic exploration have revealed much information about the atmosphere and geological history of the planet.
Mars has a rocky surface that includes plains, mountains, volcanoes and canyons. It has one of the largest canyons in the solar system, the Valles Marineris. There is also Mount Olympus, which with an elevation of 21,287 meters is the highest in the solar system.
The name of this planet comes from Roman mythology, where Mars was the god of war, equivalent to the Greek god Ares. The choice of the name is due to its reddish color, which resembles the color of blood linked to wars.
Characteristics of Mars
The main characteristics of Mars are:
- It is known as the “red planet”.
- It is the second smallest planet in the solar system.
- It is located 228 million kilometers from the Sun.
- It has an average temperature of -65 °C.
- It has two moons called Phobos and Deimos.
- Numerous missions launched from Earth visited it to study it and search for water and past life forms.
Location and dimensions of Mars
The orbit of Mars is behind that of the Earth, 228 million kilometers from the Sunjust before the Asteroid Belt that divides the solar system. Its distance from the Sun and the composition of its atmosphere explain its low temperatures, which reach -65°C.
Mars has a size of 6,779 kilometers in diametermaking it the second smallest planet in the solar system. Making a complete revolution around the Sun takes 687 Earth days, while its rotation time is very similar to that of the Earth: it takes 24.6 hours to complete one rotation on its own axis.
Composition of Mars
The surface of Mars is characterized by the presence of minerals such as iron oxides, which contribute to the characteristic red color of the planet. Additionally, other minerals such as sulfates and clays suggest the presence of water in the past.
Basalt rocks, which make up most of the Martian crust, are an indication that the planet has once experienced intense volcanic activity. In fact, Mars is home to Mount Olympus, the largest known volcano in the solar system. With an approximate height of 21,287 meters, it far exceeds the elevation of Mount Everest, the highest structure on Earth.
Geological research on Mars has been deepened in recent decades by robotic missions such as NASA rovers, which have allowed detailed data to be obtained on the mineralogical composition and geological characteristics of its surface.
Mars atmosphere
The Martian atmosphere is relatively thin relative to that of the Earth and is composed of more than 95% carbon dioxide. In much smaller proportions, nitrogen and argon are found.
Temperatures on Mars vary greatly depending on the time of day. During the day, they approach winter temperatures on Earth and can reach as low as 10°C or 20°C. But Mars’ thin atmosphere cannot keep up with the Sun’s heat, and at night they drop sharply to -129°C. Thus, the average temperature is -65 °C.
The surface of Mars also experiences strong wind storms. These storms can leave the planet covered in dust for weeks and generate tornadoes similar to those that occur on Earth.
Moons of Mars
Mars has two small moons called Phobos and Deimos.
- Phobos. It is the largest moon of Mars and has a diameter of approximately 22.2 kilometers. It was discovered by the American astronomer Asaph Hall in 1877. It orbits very close to Mars, just 6,000 kilometers away, and is getting closer and closer, which allows us to calculate that in about 50 million years it will disintegrate due to the planet’s gravity. or it will crash against its surface.
- Deimos. It is the smallest moon of Mars, with a diameter of approximately 12.4 kilometers. It was also discovered by Hall, a few days before discovering Phobos. Unlike Phobos, it orbits Mars at a greater distance (about 23,500 kilometers) and its surface has fewer craters, suggesting that it has experienced fewer impacts over time.
Explorations to Mars
There have been many space missions destined to discover Mars. So far, none have had a crew. Only more or less automated robotic devices have been sent, designed for exploration, atmospheric analysis and sample collection.
Mariner 4, in 1964, was the first mission to fly over Mars. Viking 1 and 2, in 1975, were the first missions to land on the planet. Each probe carried a lander and an orbiter, and they performed biological and geochemical analyzes on the surface.
Years later, the Mars Pathfinder mission in 1997 was the first to explore the Martian surface through a robotic vehicle. In recent years, two new explorations were launched: Curiosity in 2012 and Perseverance in 2020, which reached Mars in 2021.
Water and life on Mars
The question of the current or past existence of water and life on Mars remains one of the key goals of space exploration and future missions and discoveries are expected to provide more information.
Geological features have been identified that suggest the presence of ancient rivers, lakes and oceans, which suggests that Mars may have had abundant liquid water on its surface in the past.
Currently, it was confirmed that water ice exists at its poles and that salt water appears in a liquid state in certain seasons and specific regions.
The conditions on the Martian surface, mainly the intense radiation it receives and the thin atmosphere, make known life forms not possible. Missions like NASA’s Perseverance aim to search for evidence of signs of past life on the planet.
References
- NASA Science. (2024). All about Mars. https://spaceplace.nasa.gov/
- Rodríguez, H. (2023). These are the 8 planets of the solar system. National Geographic Spain. https://www.nationalgeographic.com.es/
