Jupiter is crucial to the evolution of the solar system. According to existing theories, the formation of Jupiter 4.6 billion years ago and its strong gravitational field played a key role in determining the orbits of other solar system planets and the shape of the solar system’s gas and dust disks, as well as the distribution of stars and the formation of the main asteroid belt. Jupiter also played its part in the origin of life, absorbing a large number of asteroids that could have collided with Earth.
Understanding the history of Jupiter’s formation is important for understanding the evolution of the early solar system. A paper by Konstantin Batygin, professor of planetary science and astrophysics at the California Institute of Technology, and Fred C. Adams, professor of physics at the University of Michigan, was recently published in the journal Nature: Astronomy. The article describes one of their studies on Jupiter’s original state. They found that just about 3.8 million years after the first solid matter of the protoplanetary disk in the solar system, Jupiter was 2 to 2.5 times larger than it is today, and its magnetic field was about 50 times stronger than it is today.
In celestial mechanics, scientists generally attribute the evolution of the solar system entirely to the interaction of Jupiter and the Sun. With the accumulation of observational data, Jupiter’s position in the formation of the structure of the solar system is increasing. Therefore, the complete process of Jupiter’s origin and structural evolution is regarded as a key milestone in the early evolutionary history of the solar system. But the details and timeline of the stages of Jupiter’s evolution remain largely a mystery due to the uncertainties inherent in Jupiter’s accretion model.
The researchers analyzed Jupiter’s two moons, Callisto and Ganymede. Both moons are small and very close to Jupiter – their orbits are even closer to Jupiter than Io. Europa is the smallest of the “Galileo moons” and the closest to Jupiter. Both the orbital planes of Ganymede and Callisto are slightly inclined to Jupiter’s equatorial plane, with little difference in orbit, which allowed the researchers to calculate Jupiter’s original size. The volume of the primordial Jupiter is said to be equivalent to more than 2,000 Earths, almost twice as large as today (1,321 Earths).
The discovery is significant because it bypasses the uncertainties found in traditional planet-forming models. Previous models have often relied on the ability of the gas to absorb or scatter electromagnetic radiation, the accretion rate, and assumptions about the mass of Jupiter’s inner core. The team took a different approach, focusing on directly observable physical quantities such as Jupiter’s angular momentum and Ganymede’s orbital dynamics.
The results also provide a new perspective for the study of exoplanets. The existing theory is that the formation of gas giants such as Jupiter began with the rapid accretion of solar nebulae gas by the planetary core composed of rocky and icy materials. The new study is a breakthrough refinement of the traditional model by accurately determining the size, rotation rate, and magnetic field environment of Jupiter in its original state.
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