NWA 12774 Study Points to 3,300-Km Lost Protoplanet Slightly Smaller Than Mars
Updated
Updated · ScienceAlert · Jun 9
NWA 12774 Study Points to 3,300-Km Lost Protoplanet Slightly Smaller Than Mars
3 articles · Updated · ScienceAlert · Jun 9
Summary
A new analysis of the 2019 Sahara meteorite NWA 12774 estimates the angrite parent body could have reached a 3,300-km radius, implying an early protoplanet just smaller than Mars.
Aluminum-rich clinopyroxene in the half-kilogram meteorite formed under high pressure, and the team’s geobarometric model argues such conditions fit a large magmatic body rather than a small asteroid.
The study puts the body's minimum radius near 1,000 km, with a likely size around 1,800 km—slightly wider than the Moon—depending on how shallowly the crystals formed in its magma reservoir.
Angrites make up just 0.09% of meteorites found on Earth and are among the oldest igneous rocks known, preserving evidence from the Solar System's violent first few million years.
Researchers say the protoplanet's destruction remains unknown, but the finding suggests other vanished worlds may still be identifiable in meteorites already sitting in collections.
A meteorite has revealed a lost planet. What made this ancient world so different from Earth or Mars?
If one lost world is confirmed, how many more vanished planets does our solar system’s history hide?
Meteorite NWA 12774 Uncovers a Lost, Moon-to-Mars-Sized Protoplanet in the Early Solar System
Overview
The discovery of the meteorite NWA 12774, found in 2019 and under study as of June 2026, marks a major breakthrough in understanding the early solar system. Unlike most meteorites that come from shattered asteroids, NWA 12774 is the first direct evidence of a large, lost protoplanet that once existed but was ultimately destroyed. This rare fragment shows that some meteorites originate from much larger celestial bodies, offering new insights into planetary formation and the dynamic history of our solar system. The study of NWA 12774 opens a unique window into these ancient, vanished worlds.