📷 Image Credits: WION
The early shape of our Solar System was recently discovered to be more like a doughnut than a flat disk. This intriguing revelation came from an in-depth study of iron meteorites originating from the outer reaches of the Solar System, shedding light on our cosmic history. Planetary system formation typically begins in a molecular cloud of gas and dust drifting through space. As a portion of the cloud collapses under its own gravity, it starts spinning and forms the seed of a nascent star, surrounded by a rotating disk that feeds into the growing protostar. Smaller clumps within the disk evolve into protoplanetary seeds, eventually leading to the formation of planets or smaller objects like asteroids. Observations of other stars have shown similar disks with gaps created by planets consuming dust as they orbit.
A team of researchers led by planetary scientist Bidong Zhang from the University of California, Los Angeles, discovered that the composition of asteroids in the outer Solar System implies a toroidal cloud of material rather than a flat disk with concentric rings during the Solar System’s early stages. Iron meteorites arriving from the outer regions of the Solar System are rich in refractory metals like platinum and iridium, which can only form in hot environments near a forming star. These meteorites must have originated in the outer regions and moved outward as the protoplanetary disk expanded. The latest calculations suggest that a toroidal protoplanetary structure would have facilitated the migration of these metal-rich objects towards the outer edges of the Solar System.
As the Solar System evolved, the disk’s gaps prevented rocks from migrating back towards the Sun, particularly after Jupiter’s formation, which likely created a physical gap, trapping metals in the outer disk. The research, detailed in the Proceedings of the National Academy of Sciences, provides crucial insights into the formation and early dynamics of our Solar System, highlighting the fascinating doughnut-shaped origins that set the stage for the celestial bodies we know today.
