Study finds Earth formed solely from inner Solar System material, challenging water origin theories
Researchers at ETH Zurich report that Earth’s building blocks came almost entirely from inner Solar System sources, with little to no contribution from beyond Jupiter.
Planetary scientists Paolo Sossi and Dan Bower of ETH Zurich analyzed isotope data from meteorites linked to Mars, Vesta and other sources, employing ten different isotope systems rather than the usual two. Their calculations indicate that virtually all of Earth’s material originated in the inner Solar System, with outer-Solar-System contributions below two percent, if any. The findings dispute the prevailing hypothesis that water-rich bodies from beyond Jupiter delivered a significant portion of Earth’s water.
The study, published in Nature Astronomy, also notes that Earth’s composition mirrors that of Mars and Vesta, implying a stable, local accretion environment. Jupiter’s early formation likely acted as a barrier limiting material exchange between the inner and outer regions. The authors now aim to explain how sufficient water existed in the hot inner disk and to explore similar processes in exoplanetary systems.
Why it matters
It reshapes our understanding of how Earth and its water formed, affecting models of planetary development.
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