How do terrestrial planets like Earth form and evolve to enable life to exist? This is what a recent study published in Nature hopes to address as a pair of scientists from the Southwest Research Institute (SwRI) and Yale University investigated the geophysical and chemical processes responsible for the formation and evolution of terrestrial planets. This study has the potential to help scientists better understand the mechanisms for how life as we know it could evolve on worlds like Earth.
For the study, the researchers used computer models to examine how the final 1 percent of a planet’s formation could play an enormous role in determining if a terrestrial planet could host life as we know it, as seen on Earth. The team specifically focused on late accretion, with accretion being the process of rocks and dust clumping together to form a planetary body. In the end, the determined that late accretion changes, specifically impacts, play a significant role in determining the outcome of a terrestrial planet, including atmosphere, surface characteristics, plate tectonics, and water content.
Diagram depicting the evolution of Earth, Venus, and Mars. (Credit: Southwest Research Institute)
“Impact histories should play a critical role in the search for habitable exoplanets like Earth,” said Dr. Simone Marchi, who is a SwRI scientist and lead author of the study. “The habitability of a rocky planet depends on the nature of its atmosphere, which is tied to plate tectonics and mantle outgassing. The search for Earth’s twin might focus on rocky planets with similar bulk properties — mass, radius and habitable zone location — as well as a comparable collision history.”
The team emphasized how large impacts could play the largest role in determining a planet’s evolution and whether life as we know it could exist there.
What new discoveries about terrestrial planet 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, EurekAlert!