A recent discovery of a meteorite has provided scientists with new insights into the formation of Earth, shedding light on the presence or absence of crucial elements in the planet's structure. This finding, published in Science Advances, challenges existing theories about the formation of our planet and explains why Earth and Mars are depleted in moderately volatile elements (MVEs).
Researchers from Arizona State University, Caltech, Rice University, and MIT have analyzed iron meteorites, remnants of the metallic cores of early planetary building blocks. Their findings reveal that planetesimals, the rocky objects that formed the early solar system, were unexpectedly rich in MVEs. This discovery challenges the previous understanding that MVEs were lost over time due to incomplete condensation in the early solar system or escape during planetesimal differentiation.
The study suggests that the early planetesimals retained their MVEs, implying that the building blocks of Earth and Mars lost these elements later, during a period of intense cosmic collisions that shaped their formation. This suggests that the progenitors of Earth and Mars were not initially deficient in these elements, but rather lost them during their collisional growth.
This new understanding of planet formation has significant implications for our understanding of the evolution of habitable planets. MVEs, such as copper and zinc, play a crucial role in planetary chemistry and are often vital for components like water, carbon, and nitrogen. Understanding the evolution of MVEs over time provides insights into why Earth became a habitable world.