According to our current models, the Planet Jupiter has played an important role in the development of the solar system. On the one hand, its formation (approx. 4.6 billion years ago) and the strong gravity should play a decisive role in the design of the orbital paths of the other solar planets, the pane of gas and dust from which they were formed, and the distribution of the planets and the formation of the main belt. Scientists have also theorized that Jupiter played a role in the development of life by absorbing asteroids that could have influenced the earth.
The understanding of Jupiter's history of education is therefore of crucial importance to understand how the early solar system has developed. In a recently published work, astronomers Konstantin Batygin and Fred C. Adams carried out a detailed examination of Jupiter's original state. Their results show that 3.8 billion according to the solar system after the first fixed bodies in the protoplanetary fog of the solar system were 2 to 2.5 times as large as it is today. They also found that it had a magnetic field 50 times more than today.
Fred C. Adams is the professor of physics and director of the Leinweber Center for theoretical Physics (around LSA) at the University of Michigan. The paper, in which its results were described “Determination of the original physical state of Jupiter”, recently appeared on May 20, 2025 in the Nature Astronomy magazine.
In heavenly mechanics, the traditional paradigm, in which the development of the solar system was only attributed to the influence of Jupiter and the sun, was deeply rooted. However, observations have increasingly emphasized the importance of Jupiter for the sculpture of the architecture of the solar system. Therefore, the full history of Jupiter origins and structural evolution is seen as an important milestone in the early development of the solar system. However, the details and the time of the formation of Jupiter remain heavily tangible due to the inherent uncertainties of accretion models.
Batygin and Adams Amalhea and Thebe, two of Jupiter's inner satellites examined for their study. This family of satellites is Jupiter with a small mass and orbits even closer than IO, the smallest and the closest to existing Jupiter Galilean moons. Both satellites have slightly inclined orbital discrepancies that enabled Batygin and Adams to calculate the original size of the Jupiter. According to her results, Jupiter once had a volume of more than 2,000 earths, about twice as high as its current volume of 1,321 earth. As Batygin said in a CalTech messages:
“Our ultimate goal is to understand where we come from and to record the early phases of planet formation is of crucial importance for solving the puzzles. This brings us closer to the understanding of how not only Jupiter but the entire solar system. What we have created here is a valuable benchmark.
These findings are particularly important because they deal with traditional uncertainties in the planetary educational models. These are often based on assumptions about the ability of a gas, electromagnetic radiation, accretion rates and the mass of Jupiter core (consisting of rock and metal). Instead, the team focused on directly measurable quantities, including the preservation of the angle impulse of Jupiter and the orbital dynamics of its moons.
The analysis of Batygin and Adams provides a crucial image of one of the critical development phases of Jupiter, which is subject to uncertainty in the past. Essentially there is an insight into the time when the solar fog from which the planets formed evaporated. This was a critical transition point where the building blocks of the planets disappeared and the original architecture of the solar system was created. “It is astonishing that even after 4.5 billion years, there are still enough indications that we can reconstruct the physical condition of the Jupiter at the beginning of its existence,” said Adams.
These results could also add new insights into theories of planet formation, which could have an impact on exoplanet studies. These theories suggest that Jupiter and the gas giants quickly bordered the solar fog as rocky and icy material (which formed the core of these planets). This new study is based on traditional models by providing more precise measurements of the size of jup readers, spin rate and magnetic conditions if it was still in an original state.
Her research was financed by CalTech, David and Lucile Packard Foundation, the National Science Foundation (NSF), the University of Michigan and the Leinweber Center for Theoretical Physics.
Further reading: CalTech, nature
