The difference between the inner and the outer solar system stands in the ring structure, which existed a long time ago on the planet that surrounded the Sun. This comes from Ramon Brasser, from the Tokyo Institute of Technology, and from Stephen Mojzsis, from the University of Colorado Boulder. Together, they combined the data they have from the observations of the discs and the computer simulations of Jupiter’s formation.
We know that the solar system is divided between the inner rocky planets and the asteroids and the outer gas planets. They have their border between the two regions that lay between the asteroid belt and Jupiter. We can see the differences through carbon – the elements are much more abundant in the outer part of the solar system than in the rocky planets and asteroids. Scientists believe that the material from the Sun’s circumstellar disc was also divided when it comes to its composition.
For an unknown reason, the material full of carbon that’s placed in the outer solar system did not go into the inner solar system. There is also one possible explanation: it appeared during the formation of Jupiter. The theory suggests that the gas giant gathered mass, and it prevented the dust from reaching the inner solar system.
Both Brasser and Mojzsis come with arguments to disapprove of this theory. They started to create simulations of the early solar system, and they showed that Jupiter was not able to gather mass fast enough to create this barrier. They started to look for an alternative explanation. They looked for data from the ALMA telescope from Chile, which is known to observe various ring structures in the circumstellar disks of young stars. They believe that it is probable that similar rings existed around the Sun when the planets start forming. If this is true, it means that they couldn’ve made regions with high-pressure gas and dust. This would have been quite difficult, but not impossible.