Mars is the second smallest planet in the solar system and the fourth largest from the sun. It has a solid, dusty, cold, and desert-like surface. Its name comes from Roman mythology, in honor of the god of war (the reddish color of its surface represents the blood spilled in battle). It is also known as the "Red Planet" and can be seen from Earth. Many people wonder why Mars is red.
Therefore, we are going to dedicate this article to telling you why Mars is red, what its characteristics are, and what makes it this color.
Key features
Mars has an elliptical orbit like Earth, so the positions and distances between the two planets are not always the same. On average, Mars is 230 million kilometers from Earth. According to scientific calculations, the farthest is 402 million kilometers and the closest is 57 million kilometers.
The Red Planet takes two Earth years to orbit the Sun and 24 hours and 37 minutes to rotate . Another similarity to the terrestrial planets is that its axis is tilted at 25 degrees (23,4 degrees relative to Earth). It has a diameter of 6.780 kilometers (almost half that of Earth) and is 228 million kilometers from its bright star.
Mars is characterized by distinct seasons, polar ice caps, valleys, canyons, and volcanoes , such as Valles Marineris (a canyon system that extends across vast areas of the surface). Additionally, there is Olympus Mons, the largest volcano in the solar system detected so far on Mars, which is three times taller than Mount Everest, Earth's tallest mountain.
It has two small moons, Phobos and Deimos, discovered in 1877. They are characterized by their low mass and elliptical shape, due to their weak gravitational pull, which prevents them from forming a spherical shape. Most of them are satellites of the solar system.
Phobos is the largest moon and scientific calculations estimate that it will collide with the Red Planet in about 50 million years.
Temperature and structure of Mars
The temperature on Mars fluctuates between 20°C and -140°C. These large temperature differences are due to the fact that the atmosphere is too thin to retain the heat it receives from the sun.
This contrast between daytime and nighttime weather can cause very strong winds, which can cause dust storms. Once the storm subsides, it could take months for all the dust to settle.
Mars is a rocky planet with a crust ranging from 10 to 50 kilometers deep , a substance rich in minerals such as silicates and nutrients such as magnesium, sodium, potassium and chlorine (characteristic of terrestrial soils that allow the growth of plants).
The reddish color is due to the richness of iron oxide on the surface. At greater depths, iron dominates, and at its dense core lie various metals such as iron, nickel, and sulfur.
The surface of Mars shares many similarities with the topography of Earth, such as volcanoes, impact craters, crustal movement, and atmospheric conditions (such as dust storms), which are characteristic of Martian landforms.
It does not have a global magnetic field, but regions of the crust in the southern hemisphere are highly magnetized, possibly traces of a larger field dating back some 4 million years.
Based on the results of several explorations, scientists believe that Mars may have had a history of ancient river networks, deltas, and lakes, and that the planet may have experienced widespread flooding around 3.500 billion years ago . It is now confirmed that water exists on the Red Planet, but the atmosphere is too thin for it to remain liquid at the surface.
why is mars red
According to the experts, published in the journal Scientific Reports, the origin may be the intense oxidation of pyrite in an oxygen-free atmosphere. Because when dissolved, the particles of this mineral -composed of almost equal amounts of iron and sulfur- produce precipitates of iron oxide and sulfate, which have the characteristic red color.
During dissolution, iron disulfide pyrite (FeS2), the most common species on Earth, is capable of producing highly reactive species, including hydrogen peroxide, commonly known as oxygenated water, and a very unstable set of free cells.
Therefore, their work shows that the dissolution of pyrite particles releases an oxidizing power that works even in an oxygen-deficient atmosphere like that of Mars. To reach this conclusion, the scientists combined computer models and laboratory experiments. Specifically, they designed a reactor to record the formation and decomposition of these species in a controlled atmosphere using spectrophotometry and sensors.
The data obtained show that the hydrogen peroxide generated on the pyrite surface reacts with the iron released during dissolution through the so-called 'Fenton reaction', forming a large amount of free radicals in solution. This is the reason why Mars is red.
atmosphere and life
Mars' atmosphere is thin and fragile, offering little protection against impacts from meteorites, asteroids, or comets. It is composed of 90% carbon dioxide with small amounts of nitrogen and argon.
The water vapor is scarce, but enough to form clouds of a certain light consistency, similar to those that exist on Earth. However, due to the pressure and temperature conditions, no precipitate will form.
Scientists believe that in order to find life on a celestial body, there must be liquid water. Evidence from space missions suggests that there was a vast ocean in the northern hemisphere of Mars about 4.300 billion years ago (and may have existed for 1.500 billion years).
That watery past, combined with a denser and more stable atmosphere, could have provided favorable conditions for the development of life. Currently, the search is not for the presence of living organisms, but rather for signs of past life , when the Red Planet was warmer, covered in water, and conditions were conducive to the development of life.
