The two small and irregular Martian moons may have been the leftovers of a massive collision.
A new study published in the Nature Geoscience journal rewrites the history of Martian moons. The two satellites that can be seen now orbiting the planet are only the remains of the satellite fleet that Mars once seemed to have.
Until now, scientists believed that the two Martian moons were asteroids that got drawn into the planet’s gravitational field. However, the regular and constant orbit of the two moons could not be explained by this theory, as asteroids do not prove to be such obedient satellites.
The new research suggests that the space rocks and many others were created by a massive impact between an asteroid and Mars. The destruction of the asteroid threw over into space a lot more satellites than we can now see next to the planet.
At the present moment, the Red Planet has only two moons, Phobos, and Deimos.
For some time now, scientists tried to prove that the two moons have been created by an impact. The theory is contradicted by other astronomers that say that the satellites are too small to have been set up by an impact. Phobos is 14 miles wide, and Deimos has 8 miles in length.
The Belgian researchers introduced a new variable in the model. A third larger moon could have co-existed with the two small satellites. All of them might have resulted from the same impact.
The fate of the third moon was to disappear into space.
The Borealis basin on Mars was long suspected by scientists to have been produced by a massive collision. The crater covers two-fifths of the surface. Researchers estimated that the object that might have created the basin had a length of 1,250 miles.
However, a collision with an object that big would have thrown into space hundreds of rocks with the dimension of Phobos and Deimos. As to explain the difference in mass, the scientists came up with the idea of a larger moon and other rocks that may have been projected into space after the impact.
Out of the materials created by the explosion, only Phobos and Deimos remained close to the planet. The rest of them went on into a space journey of their own, as the gravitational field on Mars was not strong enough to induce them a steady orbit.
But for a certain period of time in the history of Mars, the planet might have been surrounded by a disk of space debris and rock materials that remained after the collision. The materials thrown into the orbit would have included a 125 miles moon.
The gravitational force of Mars and the one of the larger moon were powerful enough to keep small rocks close together. In time, the ring of space debris dissipated into space, and only Phobos and Deimos remained to orbit the planet.
As new and exciting the new model may be, scientists now face a greater problem – finding the large ex-satellite of Mars.
Image Source: Wikipedia
