Ancient rings encompassing the Sun could have divided the solar system
The clear divide between the inner and external solar system is the heritage of a ring structure that existed a very long time before the planet-forming disc that surrounded the Sun. That is the conclusion of Ramon Brasser at Tokyo Institute of Technology and Stephen Mojzsis at the University of Colorado Boulder, who have consolidated computer simulations of Jupiter's formation with perceptions of the discs encompassing youthful stars.
The solar system is divided between the inner rocky planets and asteroids, and the external gas giants – with the border between the two regions lying between Jupiter and the asteroid belt. This difference can be quantified in terms of carbon – with the element being substantially more abundant in the external part of the solar system than it is in the ...