A new analysis of magmatic iron meteorites challenges traditional theories about why Earth and Mars are depleted in moderately volatile elements.
Moderately volatile elements (MVEs) like copper and zinc play a crucial role in planetary chemistry, often accompanying life-essential elements such as water, carbon, and nitrogen.
Understanding their origin provides vital clues about why Earth became a habitable world.
Earth and Mars contain significantly fewer MVEs than primitive meteorites (chondrites), raising fundamental questions about planetary formation.
The new study takes a fresh approach by analyzing iron meteorites — remnants of the metallic cores of the earliest planetary building blocks — to uncover new insights.
“We found conclusive evidence that first-generation planetesimals in the inner Solar System were unexpectedly rich in these elements,” said Dr. Damanveer Grewal, a researcher at Arizona State University.
“This discovery reshapes our understanding of how planets acquired their ingredients.”
Until now, scientists believed that MVEs were lost either because they never fully condensed in the early Solar System or escaped during planetesimal differentiation.
However, the new study reveals a different story: many of the first planetesimals held onto their MVEs, suggesting that the building blocks of Earth and Mars lost theirs later — during a period of violent cosmic collisions that shaped their formation.
Surprisingly, the authors found that many inner solar system planetesimals retained chondrite-like MVE abundances, showing that they accreted and preserved MVEs despite undergoing differentiation.
This suggests that the progenitors of Earth and Mars did not start out depleted in these elements, but instead, their loss occurred over a prolonged history of collisional growth rather than incomplete condensation in the Solar Nebula or planetesimal differentiation.
“Our work redefines how we understand the chemical evolution of planets,” Dr. Grewal said.
“It shows that the building blocks of Earth and Mars were originally rich in these life-essential elements, but intense collisions during planetary growth caused their depletion.”
The study was published in the journal Science Advances.
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Damanveer S. Grewal et al. 2025. Enrichment of moderately volatile elements in first-generation planetesimals of the inner Solar System. Science Advances 11 (6); doi: 10.1126/sciadv.adq7848
