A reorganization of the solar system's outer planets would have occurred during the early stages of its formation, according to a new study of two Trojan Asteroids of Jupiter.
The American astrophysicist David Nesvorny and his colleagues at the Southwest Research Institute have studied a rare pair of asteroids called Patroclus and Menoetius, which is approximately the same distance from the Sun as Jupiter, one in the banana front and the other behind the gas giant.
These asteroids will be the focus of NASA's Lucy mission to be launched in 2021
Patroclus and Menoetius are about 113 km wide and circulate around each other as they circulate the sun. They are the only known binary system in the Trojan Asteroid Population of Jupiter. In astronomy, the term "Trojan" is used to refer to a small object that shares a relationship with two other larger bodies.
Current work shows that the presence of Patroclus and Menoetius, as well as others in Jupiter course, would be the result of an early planetary reorganization in our system. The pair would have been formed from the original disc of material in addition to Neptune.
Simulations indicate that the presence of the celestial couple today at this site indicates that the dynamic instability between the giant planets must have taken place during the first 100 million years of solar system formation. These objects were probably caught during a dramatic period of dynamic instability during a collision between the solar system giant planets.
This great upheaval would have driven Uranus and Neptune outward, where they met a large population of small bodies that would be the origin of the current objects of the Kuiperbelt, which revolves around the solar system.
According to the researchers, several small bodies of this primordial Kuiper band were spread inward, and some of them became Trojan asteroids. In fact, the latest simulations of the formation of small bodies suggest that binary systems like Patroclus-Menoetius are remnants of the very first moments of the system's birth.
Current observations of the Kuiper belt show that these binary systems would have been common during system genesis. "There are only a few left in Neptune's course. The question is how they survived until today," said scientist William Bottke.
The early solar instability model for solar systems presented in current works also has important implications for the rocky planets, especially with concerning the origins of the great craters of the moon, mercury and march, which were formed about 4 billion years ago.
According to this model, the meteorites digging these craters are less likely to reach distant areas of the solar system. This may mean that they were made from the remains of small bodies from the process of forming rocky planets. The details of these works are published in the journal Nature Astronomy.