The Formation of Earth and the Role of Cosmic Events in the Emergence of Life

Earth is currently the only known planet where life exists, thanks to the presence of liquid water and a stable atmosphere. However, when Earth formed, conditions were not suitable for life. A new study by researchers from the Institute of Geological Sciences at the University of Bern has shown that Earth’s chemical composition was completed three million years after the solar system’s formation, initially preventing the emergence of life.

Early Earth Formation and Chemical Challenges

Earth formed from a gaseous and dusty cloud rich in volatile elements essential for life, such as hydrogen, carbon, and sulfur. However, in the inner solar system, close to the Sun, these elements were scarcely present due to high temperatures. The solid rocky materials that formed the planets did not incorporate these gaseous elements, leaving early Earth with minimal amounts of them.

Researchers used isotope and elemental data from meteorites and terrestrial rocks to reconstruct Earth’s formation process. The results showed that Earth’s chemical composition was completed within three million years of the solar system’s formation.

Using Precision Techniques to Measure Earth’s Age

The research team relied on a precise chronological measurement system based on the radioactive decay of manganese-53 to determine Earth’s exact age. This isotope existed in the early solar system and decayed into chromium-53. This method allowed for age determination with a precision of less than a million years for materials billions of years old.

Krotash confirmed that these measurements were possible due to the internationally recognized expertise and infrastructure at the University of Bern for analyzing extraterrestrial materials, providing the study with significant accuracy in its results.

The Role of Cosmic Chance in the Emergence of Life

The study revealed that the chemical signature of primitive Earth was completed in a relatively short time. The findings suggest that a subsequent collision with another planet, called Theia, may have been the decisive factor that made Earth suitable for life. Theia is believed to have formed further out in the solar system, where volatile elements like water accumulated.

The results align with the hypothesis that early Earth was a dry, rocky planet and that the collision with Theia brought volatile elements to Earth, making life possible.

Conclusion

The study provides a deeper understanding of the early solar system’s processes and offers evidence of when and how planets suitable for life could form. The results indicate that Earth’s suitability for life was not due to continuous evolution but was likely the result of a chance event, the late collision with a water-rich body. This discovery suggests that life’s suitability in the universe is not a given, opening the door to further research on the collision between primitive Earth and Theia to understand the physical and chemical properties of Earth and the Moon more deeply.