Astronomers come closer to understanding how Mercury formed

Simulations of the formation of the solar system have been largely successful. They are able to reproduce the positions of all major planets and their orbital parameters. However, with current simulations, it is very difficult to accurately calculate the masses of the four terrestrial planets, especially Mercury. New research suggests we need to pay more attention to giant planets in order to understand the evolution of smaller planets.

of all rocky interiors planet Mercury is the strangest planet in the solar system. Not only does it have the lowest mass, but it also has the largest core compared to its size. This poses a major challenge for planetary formation simulations. Because it is difficult to build such a large core without growing a proportionally large planet.

A team of astronomers recently investigated some possibilities for explaining Mercury’s strange properties by running simulations of the formation of the solar system. In the early solar system, instead of a neat series of planets, there was a protoplanetary disk of gas and dust. Embedded in its disk are dozens of planetesimals that eventually collide, fuse, and grow into a planet.

Astronomers believe that the inner rim of the protoplanetary disk was probably relatively starved of material. Also, in that young system, giant planet It did not appear in the current orbit. Instead, they moved from where they were originally formed to their current location. As these giant planets moved, their inner disks could become unstable, removing even more material.

Putting these ideas together has allowed astronomers to construct the formation history of Mercury.Originally the Uchihara planetary system disk It contained many planetesimals, but pulled apart much of the material that makes up the planet as the giant planet shifted and migrated. The remaining planetesimals collided with each other in a series of frequent collisions, resulting in the dumping of many heavy metals onto the innermost planet, creating Mercury’s large core.

The model was able to capture Mercury’s core size, but the simulation still failed to get the planet’s overall mass correct. Simulations typically produced Mercury two to four times more massive than it actually is.

There remains an open question as to how Mercury was born.of Astronomer It seems that more attention should be paid to the chemical nature of protoplanetary diskin particular, focuses on how dust particles can stick together and survive the intense radiation environment in Mercury’s orbit.

The work is arXiv preprint server.