Earth’s composition was modified by collisional erosion

A recent study published in Science brings new constraints on planet formation. It highlights the role of collisions in shaping planets and affecting their composition.

Artist view of the Solar System in formation. (Image: M. Kornmesser, ESA/NASA.)

The Earth is an active planet 4.5 billion years old. This long evolution makes understanding its formation challenging. Meteorites are remnants of the early history of the solar system formation and bring clues to the formation of planets. Analysing neodymium enables to refine genetic links and identify early processes of planetary differentiation.

Researchers analysed the composition of neodymium in primitive meteorites. These results show that despite being considered as building blocks of the planets, primitive meteorites display a different composition compared to the Earth. Earth and the rocks from the surface of proto-planets are enriched in the isotope 142-neodymium. This composition can be explained by repeated collisions in the first million years of the Solar System, that destroyed up to 20% for Earth’s mass.

colissional erosion
Collisional erosion, or loss of primordial crusts of asteroids during accretion, shapes the composition of planets. Primitive crusts are enriched in radioactive elements compared to the mantle. Collisions lead to the destruction of primitive crust, leaving the planet depleted in radioactive elements compared to what was previously thought. Radioactive elements are essential to heat production in our planet and its geological activity. (Graph: ETH Zurich / Paul Frossard)

The study was performed at the Laboratoire Magmas et Volcans, Clermont-Ferrand in France (UCA/CNRS/IRD). Paul Frossard, the lead author is now a postdoctoral researcher at the Institute of Geochemistry and Petrology of the ETH Zürich, working with Prof. Maria Schönbächler.


Paul Frossard, Claudine Israel, Audrey Bouvier, Maud Boyet, 2022. Earth’s composition was modified by collisional erosion. Science 377, 1529-1532.


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