Jupiter trojan belt
© NASA/JPL-Caltech
Artist's impression of the Jupiter Trojan belt.
Researchers studying the lone surviving binary asteroid in the Trojan belt orbiting Jupiter have revealed that the chaos at the beginning of our solar system may have been shorter but more violent than previously thought.

A new study on the binary asteroid Patroclus-Menoetius reveals that within the first 100 million years of the solar system's existence, Jupiter and Saturn shoved Uranus and Neptune away from the sun towards the Kuiper belt, a mass of primordial celestial bodies, in a kind of cosmic eviction.

The binary asteroid consists of a pair of celestial bodies both roughly 100km (62 miles) in diameter that are found within the Jupiter Trojan belt, a mass of objects that orbits the sun in line with the gas giant of our solar system.

"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," David Nesvorny, one of the team from the Southwest Research Institute in Colorado, said in a press release.
© W.M. Keck Observatory/Lynette Cook

According to the new research, this period of chaos ended 600 million years earlier than previously thought: Patroclus-Menoetius would not have survived until now had the celestial skirmishes happened any later, otherwise the massive number of collisions which created the debris field that later became the Kuiper belt would never have occurred.

"Observations of today's Kuiper belt show that binaries like these were quite common in ancient times," says one of the researchers, William Bottke. "Only a few of them now exist within the orbit of Neptune. The question is how to interpret the survivors."

NASA is set to launch the Lucy probe in October 2021 to answer this very question by closely studying Patroclus-Menoetius among other asteroids in our system.

The findings of the study were published in the journal Nature Astronomy on Monday.