Sahara Meteorite Points to Lost World Up to 1,800 Kilometers Wide
Updated
Updated · spacedaily.com · Jul 2
Sahara Meteorite Points to Lost World Up to 1,800 Kilometers Wide
1 articles · Updated · spacedaily.com · Jul 2
Summary
Northwest Africa 12774—a fist-sized, sub-0.5-kilogram meteorite found in 2019—was identified in a new study as a fragment of a vanished protoplanet, not a small asteroid.
17.5-kilobar crystallization pressures inferred from aluminum-rich clinopyroxene drove that reinterpretation, because an asteroid could not generate such intense internal pressure.
Those pressures imply a parent body at least 1,000 kilometers in radius and possibly more than 1,800 kilometers if the crystals formed at shallow depth—roughly Moon scale.
The angrite meteorite's silica-poor chemistry also suggests the body formed from raw materials unlike those that built Earth and Mars, pointing to a distinct early planetary pathway.
Researchers say the world was most likely destroyed in early solar-system collisions, and the result now hinges on whether the new pressure tool yields the same picture in other angrites.
If our early solar system was a planetary graveyard, how many other 'lost worlds' are waiting to be found?
What does a planet chemically unlike Earth or Mars tell us about the ingredients that built our solar system?
NWA 12774: First Direct Evidence of a Lost Moon-Sized Protoplanet in the Early Solar System
Overview
The discovery of NWA 12774, a rare angrite meteorite found in the Sahara Desert, has captivated scientists because it is the first direct physical evidence of a large, lost protoplanet from the early Solar System. Angrites like NWA 12774 are exceptionally uncommon, making this find especially significant. This ancient fragment provides a tangible link to a vanished celestial body, offering new insights into planetary formation. Its unique composition and origin highlight the diversity of early planetary building blocks and reshape our understanding of how planets like Earth may have formed from the remnants of such lost worlds.