What processes are responsible for the first planets in our solar system forming? This is what a recent study published in Nature Astronomy hopes to address as a team of scientists from the United States and Germany investigated the complex geological processes that formed the first planetesimals, or young planets, in our early solar system. This study has the potential to help scientists better understand the formation and evolution of the solar system’s first planets and what this could mean for finding life beyond Earth.
For the study, the researchers conducted a series of geochemical analyses on iron meteorites to ascertain the geochemical composition of their original state billions of years ago, specifically the silicate (volcanic) rock called chondrules that comprise space rocks. This is because the rocks have melted and eroded so much over time, so the researchers have to examine radioactive isotopes to ascertain the composition of the parent body the meteorites broke away from.
The primary motivation behind the study was to fill a longstanding knowledge gap regarding how the first planets, also called planetesimals, formed and evolved. In the end, the researchers found that the first planetesimals were formed from hot impacts, as opposed to longstanding hypotheses that they formed from icy materials.
“Our work shows that this assembly process was remarkably selective from the very beginning,” said Dr. Damanveer Grewal, who is an assistant professor of Earth and planetary sciences at Yale University and lead author of the study. “The earliest bodies in the outer solar system were built from 83% to 92% chondrules, with very little of the icy, volatile-rich dust that dominates later-forming objects.”
This study holds implications for not only better understanding the formation of planets within our solar system, but also exoplanets, too. This is because while our solar system has a specific architecture such as rocky planets closer to the Sun and larger planets farther out, astronomers are discovering that the architecture of exoplanetary systems are far more complex than previously thought.
What new insights into planetary formation and evolution will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature Astronomy, EurekAlert!
Featured Illustration Credit: NASA/JPL-CalTech/T. Pyle