It's a well-known fact that Jupiter plays a vital role in the dynamics of the Solar System. As the largest planet beyond the "Frost Line," the boundary where volatiles (like water) freeze, Jupiter protects the planets of the inner Solar System from potential impacts by asteroids and comets. In addition to this "guardian" role, Jupiter has also been an "architect" planet that affected the evolution of the early Solar System and the orbits of its planets. According to new research from Rice University, Jupiter reshaped the Solar System by carving rings and gaps in the protoplanetary disk, leading to the formation of late-stage meteorites.
Their findings, detailed in a paper published in Science Advances, address one of the longest-standing mysteries in planetary science: why many primitive meteorites formed millions of years after the first solid bodies. For their study, graduate student Baibhav Srivastava and Assistant Professor André Izidoro from the Department of Earth, Environmental, and Planetary Sciences at Rice University combined hydrodynamic models of Jupiter's growth with simulations of dust evolution and planet formation.
These advanced simulations revealed that, billions of years ago, Jupiter's rapid early growth destabilized the protoplanetary disk from which all the planets formed. This was due to Jupiter's powerful gravity, which sent ripples through the disk, causing gas and dust to collect into dense bands. This prevented particles from spiraling into the Sun, causing them to coalesce into planetesimals instead. However, these bodies were not the first planetesimals that formed 4.6 billion years ago, but represent a second generation that formed 2 to 3 million years later.
This coincides with the emergence of a family of stony meteorites that formed during the early Solar System. But unlike meteorites from the first generation that melted and differentiated, chondrites contain spherical grains (chondrules) that formed from molten material that retain their original chemical composition. This essentially makes these meteorites time capsules, allowing planetary scientists to discern what conditions were like at the time. The late formation of these meteorites has mystified scientists for decades. As Izidoro explained in a Rice University news story:
Chondrites are like time capsules from the dawn of the solar system. They have fallen to Earth over billions of years, where scientists collect and study them to unlock clues about our cosmic origins. The mystery has always been: Why did some of these meteorites form so late, 2 to 3 million years after the first solids? Our results show that Jupiter itself created the conditions for their delayed birth.
In addition, it has long been a mystery how Earth and its neighbors (Venus and Mars) became clustered around 1 Astronomical Unit (AU) from the Sun, ranging from 0.72 to 1.5 AUs. As observations of extrasolar planetary systems have shown, planets in early star systems will often spiral inwards towards their stars. These results show that Jupiter suppressed the inward migration of young planets by cutting off the flow of gas and dust toward the inner Solar System. This allowed rocky protoplanets to remain in stable orbits and eventually grow into the Solar System's rocky planets.
In short, the study revealed that in addition to becoming the largest planet, Jupiter set the architecture of the entire inner Solar System. This architecture allowed for Earth to evolve and develop the conditions that would eventually give rise to life. Said Srivastava:
Our model ties together two things that didn’t seem to fit before — the isotopic fingerprints in meteorites, which come in two flavors, and the dynamics of planet formation. Jupiter grew early, opened a gap in the gas disk, and that process protected the separation between inner and outer solar system material, preserving their distinct isotopic signatures. It also created new regions where planetesimals could form much later.
These results are supported by observations of young star systems made with the Atacama Large Millimeter/submillimeter Array (ALMA). These radio observations of protoplanetary disks revealed the same ring-and-gap structures Srivastava and Izidoro noted in their simulations. “Looking at those young disks, we see the beginning of giant planets forming and reshaping their birth environment,” Izidoro said. “Our own solar system was no different. Jupiter’s early growth left a signature we can still read today, locked inside meteorites that fall to Earth.”
Further Reading: Rice University, Science Advances
