An international team of scientists has uncovered key insights into the origins of Earth’s water and the formation of small celestial bodies in our solar system

Led by researchers from Heidelberg University and collaborating with institutions across Europe, the study looks into the role of planetesimals, small, ancient bodies that played a crucial role in shaping the planets, including Earth.

Planetesimals’ role in creating Earth

The findings showed that planetesimals, formed from dust particles in the early solar system, acted as crucial reservoirs of water.

Unlike early-formed planetesimals closer to the Sun, which lost their volatile elements due to intense heat, those originating in the colder outer reaches preserved water in solid ice form. These icy planetesimals, the study suggests, delivered significant amounts of water to Earth during its formation around 4.5 billion years ago.

“The Earth accreted such small water-rich planets or their fragments in the form of asteroids or meteorites during its growth process and that is the only reason why it did not become a bone-dry planet, hostile to life,” says Dr Wladimir Neumann, first author of the study.

Finding Earth like planets

The study suggests that similar processes may have occurred in other planetary systems throughout the universe. According to the researchers, this raises the possibility of finding Earth-like planets capable of supporting life elsewhere in space.

Collaborating institutions, including TU Berlin, the German Aerospace Center, ETH Zurich, and the University of Bayreuth, contributed to the comprehensive computational models and analysis that underpin these findings. Funding from the German Research Foundation, Klaus Tschira Foundation, and International Space Science Institutes in Bern and Beijing supported this multidisciplinary research effort.

As our understanding of planetary formation continues to evolve, this study emphasises the critical role of icy planetesimals in shaping Earth’s history and potentially paving the way for the emergence of life. The insights gleaned from ancient meteorites not only deepen our knowledge of our own cosmic origins but also fuel the ongoing search for habitable planets beyond our solar system.

For more detailed insights into this groundbreaking research, the full study is available in Nature Scientific Reports. It offers a window into the complex interplay of cosmic forces that shaped our world and continues to intrigue scientists exploring the vast expanse of the universe.