In the past around Mars could be a ring, reported in an article accepted for publication in Astrophysical Journal Letters. It was formed pretolani planet, which later developed a modern Phobos, near Mars. If the assumption of scientists is correct, then astronomers will finally be able to explain the inclination of the orbit of Deimos, the second satellite of the red planet.
For a long time astronomers thought that the two moons of Mars, Phobos and Deimos, opened in 1877, when in the past was asteroids, which later fell into the gravitational trap of the red planet. However, their orbits are nearly in the same plane as the equator of Mars, which means they formed at the same time. It is noteworthy that the orbit of the outer moon, Deimos, is tilted by two degrees. At first glance, the rejection seem insignificant, but according to scientists, it’s not uncommon for moons and anomaly evidence of rapid processes in the past.
The most popular theory suggests that Phobos and Deimos formed as a result of collision of Mars with a large celestial body. However, the mass of the moons is much less than what models predict. While one of the hypotheses explains that in the past in the system there were other satellites, the other suggests that mass loss has occurred due to the fact that protopapas was ruined several times around Mars forming a ring, after which it remains stuck together again.
Matija CuK (Matija Cuk) of the SETI Institute, together with colleagues using computer simulation, we decided to test the second hypothesis and determine how Phobos looked in the past and how many cycles of destruction he could survive. In their work the researchers assumed that moons of Mars were in an orbital resonance of 3:1, which could explain the inclination of the orbit. Astronomers have considered in the model, two satellites: Deimos with its present mass and Pratolino with weight from 1 to 100 mass of Phobos.
It turned out that in order to affect the slope of Deimos, Phobos in the past had to be about 20 times more than now. In this form of protolon existed three billion years ago, until I experienced two cycles of destruction. First Phobos migrated into the outer part of the ring around Mars, where he joined with Deimos in orbital resonance and in the result of gravitational interactions pushed him into a new orbit. Protopapas began to move to the surface of Mars and was subsequently torn to pieces. One piece of wreckage fell to the planet’s surface, while the other formed a ring. Some of the stones and dust stuck together to form a new moon, and then the process was repeated.
In favor of the results obtained by astronomers, says the age of the moons. Estimated Deimos few billion years, while Phobos may be only 200 million. In addition, a few years ago, astronomers noticed that the satellite loses altitude due to gravitational interaction with the red planet, and came to the conclusion that very soon (in astronomical terms) Phobos will reach the Roche limit and fall apart, forming a new ring.
Theories about the age of Phobos may be able to test in the coming years, as the Japanese space Agency JAXA plans to send to Phobos in 2024, the spacecraft, which will collect soil samples and deliver them to the Earth. Read more about the mission, read our material.