Researchers from the College of Zurich (UZH) and the Nationwide Heart of Competitors in Analysis (NCCR) Planets performed the investigation. JupiterThe history of its formation is described in detail. Their results suggest that the giant planet moved far beyond its core and collected a large amount of material on its journey.
One of the most important open questions in planet formation theory is the origin story of Jupiter. Using sophisticated computer modelling, researchers from the University of Zurich (UZH) and the National Center of Competence in Research (NCCR) PlanetS have now shed new light on the history of Jupiter’s formation. Journal of their results. were published in The Astrophysical Journal Letters,
a curious enrichment of heavy elements
When the Galileo spacecraft released a probe by parachute into Jupiter’s atmosphere in 1995, it showed, among other things, that heavy elements (elements heavier than helium) were enriched there. At the same time, recent structure models of Jupiter based on gravitational field measurements by the Juno spacecraft suggest that Jupiter’s interior is not uniform, but has a complex composition.
Since we now know that Jupiter’s interior is not completely mixed, we would expect heavy elements to be in the deep interior of a giant gas planet because heavier elements mostly accumulate during the early stages of planet formation, Ravit Held, a co-author of the study, professor at the University of Zurich and member of NCCR Planets, began to explain. Large amounts of light can effectively attract element gases. Finding a formation scenario of Jupiter that is consistent with the predicted internal composition as well as the measured atmospheric enrichment is therefore challenging yet important to our understanding of the giant planets,” Healed says. None of them could give a satisfactory answer.
a long stay
“Our idea was that Jupiter collected these heavy elements by migrating into the final stages of its formation. In doing so, it would have gone through regions filled with so-called planets – minor planetary building blocks that formed from heavy element material. – and deposit them in their environment,” explains study lead author Sho Shibata, a postdoctoral researcher at the University of Zurich and a member of NCCR PlanetS.
Nevertheless, migration by itself is no guarantee of gathering the necessary materials. “Due to complex dynamic interactions, the migrating planet does not necessarily accumulate planets in its path. In many cases, the planet actually scatters them—not unlike a shepherd dog that scatters sheep,” explains Shibata. So the team had to run countless simulations to determine whether a migration route resulted in substantial material accretion.
“What we found was that if Jupiter formed in the outer regions of the Solar System – about four times farther from the Sun than where it is now located – and then shifted to its current position a sufficient number of planets could be captured In this scenario, it passed through an area where conditions were in favor of physical accretion—an accretion sweet spot, as we call it,” the show reports.
A new era in planetary science
Combining the constraints introduced by the Galileo probe and Juno data, researchers have finally come up with a satisfactory explanation. “This shows how complex the giant gas planets are and how difficult it is to reproduce their features realistically,” explains Ravit Held.
“It took us a long time in planetary science to reach a stage where we can finally explore these details with updated theoretical models and numerical simulations. It not only narrows the gap in our understanding of Jupiter and our solar system, but also the many observed giant planets orbiting distant stars,” Healed concluded.
Reference: “Enrichment of Jupiter’s Atmosphere by Late Planetary Bombardment” by Sho Shibata and Ravit Held, 24 February 2022, The Astrophysical Journal Letters,