Four and a half billion years ago, the solar system was a cloud of gas and dust swirling around the sun, eventually condensing and accreting to form asteroids and planets. Protoplanetary disks can be observed using telescopes, and meteorites offer clues about the composition of our solar system’s infancy. A recent study published in Proceedings of the National Academy of Sciences found that refractory metals like iridium and platinum were more abundant in meteorites formed in the outer disk, despite forming closer to the sun where temperatures were higher.
Meteorites, such as chondrites, give insight into the early history of the solar system. Many meteorites formed within the first few million years and offer evidence of planet formation. Iron meteorites, containing molybdenum isotopes, reveal the chemical composition of the protoplanetary disk in its early stages. Scientists believe Jupiter’s gravity played a role in disrupting the orbits of asteroids and causing collisions, leading to the formation of meteorites that fall to Earth.
Research using the Atacama Large Millimeter/submillimeter Array in Chile has shown that disks around other stars often resemble concentric rings, unlike our solar system. The new study suggests that the early solar disk may have had a doughnut shape, with metal-rich asteroids migrating to the outer disk as it rapidly expanded. Once Jupiter formed, it may have created a physical gap that prevented the metals from falling back into the sun, leading to higher levels of iridium and platinum in meteorites from the outer disk.
The study’s lead author, Bidong Zhang, highlights the importance of iron meteorites in unraveling the mysteries of the solar system’s formation. By studying iron meteorites, researchers can gain insights into how water was distributed in the protoplanetary disk and understand the movement of metals throughout the disk. This research sheds light on the complex processes that shaped our solar system billions of years ago and provides valuable information for understanding planetary formation.
Overall, the study reveals how refractory metals like iridium and platinum were transported from the inner solar disk to the outer disk during the early stages of the solar system’s formation. By examining meteorites and studying the composition of iron meteorites, scientists can reconstruct the history of the solar system and gain a deeper understanding of the processes that led to the formation of asteroids and planets. The findings contribute to our knowledge of planetary formation and shed light on the intricate mechanisms that shaped our solar system billions of years ago.