Scientists at the Southwest Research Institute have studied an unusual pair of asteroids and found that their existence points to previously unknown details of planetary changes in the solar system.
We are talking about space bodies called Patroclus and Menoeti, which are objects of study for the upcoming NASA mission. Objects about 70 miles wide are orbitally tied to each other and to the orbit of the Sun. They represent the only large binary object known in the population of ancient bodies, the so-called 'Trojan asteroids'.
“These Trojans appear to have been hijacked during a dramatic period of dynamic instability, when there was a 'shootout' between the giant planets of the solar system – Jupiter, Saturn, Uranus and Neptune, 'said SwRI scientist David Nesvorni, lead author of Evidence very early migration of the planets of the solar system based on observations of the Trojan asteroid Jupiter Patroclus-Menoetius, which was published in the publication Nature Astronomy. This shake-up pushed Uranus and Neptune outward, where they collided with a large primordial population of small bodies believed to be the source of today's Kuiper objects orbiting at the edge of the solar system. Many small bodies of this primordial Kuiper belt were scattered inward, and some of them were trapped in Trojan asteroids. '
In this article, scientists show that the very existence of the Patroclus-Menoeti pair indicates that dynamic instability among the giant planets must have occurred during the first 100 million years of the formation of the solar system.
The results of modeling the formation of small bodies suggest that these types of binary objects are representatives of the earliest period of the existence of the solar system, that is, when pairs of small bodies could form directly from particles of cosmic dust formed after the destruction of larger objects.
“Today's observations of the Kuiper belt show that binary objects like this were quite common in the early period,” said Dr. William Botke, director of space research at SwRI, and co-author of the paper. 'Only a few of them now exist in orbit around Neptune. The question is how to interpret survivors. '
If instability were delayed for many hundreds of millions of years, as suggested by some evolutionary models of the solar system, collisions within the primordial disk with small bodies would disrupt these relatively fragile binary objects, leaving Trojan asteroids completely non-existent. Dynamic instability in the early period could have formed more such objects, which increases the likelihood that at least one Trojan asteroid could exist. The team of scientists has created new models that show that the very existence of the Patroclus-Menoeti binary code indicates that instability arose earlier.
This early dynamic model of instability has important implications for terrestrial planets, especially with respect to the origin of large impact craters on the Moon, Mercury and Mars, which formed about 4 billion years ago. According to the new model, the impact elements that formed these craters are less likely to 'come' from the outer solar system. This could mean that they were made from small remnants during the formation of the earth's planet.
This work highlights the importance of Trojan asteroids in illuminating the history of our solar system. Much more about the Patroclus-Menoeti binary object can be learned when it is surveyed by NASA's Lucy spacecraft in 2033.
