SwRI: Scientists Find Evidence for Early Planetary Shake-up

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SwRI: Scientists Find Evidence for Early Planetary Shake-up

Post by bystander » Tue Sep 11, 2018 3:21 pm

SwRI Scientists Find Evidence for Early Planetary Shake-up
Southwest Research Institute | 2018 Sep 10

Asteroid Pair Is the “Smoking Gun” Indicating an Earlier Altercation Amongst the Giants

Scientists at Southwest Research Institute studied an unusual pair of asteroids and discovered that their existence points to an early planetary rearrangement in our solar system.

These bodies, called Patroclus and Menoetius, are targets of NASA’s upcoming Lucy mission. They are around 70 miles wide and orbit around each other as they collectively circle the Sun. They are the only large binary known in the population of ancient bodies referred to as the Trojan asteroids. The two swarms of Trojans orbit at roughly the same distance from the Sun as Jupiter, one swarm orbiting ahead of, and the other trailing, the gas giant.

“The Trojans were likely captured during a dramatic period of dynamic instability when a skirmish between the solar system’s giant planets — Jupiter, Saturn, Uranus and Neptune — occurred,” said SwRI Institute Scientist Dr. David Nesvorny. ... This shake-up pushed Uranus and Neptune outwards, where they encountered a large primordial population of small bodies thought to be the source of today’s Kuiper Belt objects, which orbit at the edge of the solar system. “Many small bodies of this primordial Kuiper Belt were scattered inwards, and a few of those became trapped as Trojan asteroids.”

A key issue with this solar system evolution model, however, has been when it took place. In this paper, scientists demonstrate that the very existence of the Patroclus-Menoetius pair indicates that the dynamic instability among the giant planets must have occurred within the first 100 million years of the solar system formation.

Recent models of small body formation suggest that these types of binaries are leftovers of the very earliest times of our solar system, when pairs of small bodies could form directly from a collapsing cloud of “pebbles.” ...

Evidence for Very Early Migration of the Solar System Planets
from the Patroclus-Menoetius Binary Jupiter Trojan
~ David Nesvorný et al
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