Scientists from Switzerland have presented a new study, where they studied some of the orbital features and the unusual location of Deimos and Phobos. They concluded that these celestial bodies were due to the destruction of the larger moon of Mars.
The small size of the celestial bodies prompted researchers to conclude that in fact the asteroids were captured in the gravitational field of Mars. However, the captured objects must follow an eccentric orbit around the planet, and this orbit will have a random tilt. Contrary to this hypothesis, the orbits of the Martian moons are almost circular, they move in the equatorial plane of Mars. To solve this problem, the researchers applied computer simulations.
So the researchers were able to trace the orbits and their change. As it turned out, the orbits of Phobos and Deimos crossed in the past. Therefore, scientists have suggested that they may have the same origin. The researchers note that a large celestial body moved in orbit and then disintegrated due to a collision with another body. Scientists suggest that Phobos and Deimos are the remains of that celestial body.
Using these results and their refined tidal theory, the researchers ran hundreds of computer simulations to track the Moon’s orbits in the opposite direction until they reached the intersection, the birth of Phobos and Deimos. Depending on the simulation, this point in time lies between 1 and 2.7 billion years ago.
Images and measurements taken by other Mars probes indicate that Phobos and Deimos are made of highly porous material. At less than 2 grams per cubic centimeter, their density is well below the Earth’s average density, which is 5.5 grams per cubic centimeter.
Researchers have been studying the moons of Mars, Phobos and Deimos, since their discovery in 1877. They are very small: Phobos is 22 km in diameter, it is 160 times smaller than the Moon, and Deimos is even smaller – its diameter is only 12 km.