In 2019, a meteorite found in the Sahara, known as NWA 12774, provided insights into a vanished planetary body from the early solar system. Classified as an angrite, this volcanic meteorite is one of the oldest igneous rocks discovered. Researchers, including Bell, Waters, and Ghiorso, proposed in a 2026 paper that the minerals in NWA 12774 indicate pressures too high for a small asteroid, suggesting it comes from a larger body, possibly a planetary embryo.
The significance of the meteorite lies in the mineral clinopyroxene, which exhibits an unusually aluminum-rich composition. Using geobarometry, the researchers estimated formation pressures of at least 17.5 kbar, implying that NWA 12774 did not originate from a small body but likely from a larger, differentiated planetesimal measuring over 1,800 kilometers in radius.
This proposed “lost planet” is inferred from pressure measurements and not named or mapped through existing astronomical knowledge. The research highlights the violent history of the early solar system, where planetesimals and embryos collided, merged, or were destroyed.
While NWA 12774 presents a unique narrative of a world’s formation and disappearance, it also emphasizes the inherent limitations of meteorite studies, as they cannot provide a complete history of their parent bodies. Still, NWA 12774 serves as a physical reminder of the early solar system’s complexity, illustrating both creation and loss. If the findings are correct, this meteorite may hold the remnants of a once-large celestial body now lost to history.
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