NWA 12774 Study Points to Lost Protoplanet Up to 1,800 Kilometers Wide

Q: Could fragments from this shattered protoplanet be the building blocks of worlds we know today, including Earth?

Yes—possibly, but only as a small part of Earth’s makeup, not as its main source. The new study on meteorite NWA 12774 argues that its parent body was not a small asteroid but a large protoplanet, perhaps as big as the Moon or even Mars. Because the meteorite formed under very high pressure, researchers say it likely came from a planetary embryo that was later destroyed in a collision during the solar system’s violent early history. Aaron Bell and colleagues say fragments from that shattered world could have been swept into other growing rocky planets, including Earth. That idea fits the broader picture of planet formation. The early solar system was built through repeated collisions and mergers among dust, planetesimals, and planetary embryos. In that sense, fragments of destroyed worlds are widely understood to have contributed material to later planets. But the evidence does not show that Earth was built mainly from this specific lost protoplanet. Other isotopic studies indicate Earth formed overwhelmingly from inner solar system material and that its bulk composition does not match any single known meteorite group. The angrite parent body also appears chemically distinct from Earth and Mars, suggesting it followed a different evolutionary path. So the most careful answer is that fragments of this lost protoplanet may well have ended up inside worlds we know today, including Earth, but as one ingredient among many in a much larger mix of early inner solar system material.

3 articles · Updated · Livescience.com · Jun 7

A new analysis of the 454-gram angrite meteorite NWA 12774 argues it may be the first definitive evidence of a vanished protoplanet that once orbited the sun.
Aluminum-rich clinopyroxene in the rock indicates formation under pressures too high for a small asteroid, pushing the inferred parent body to at least 1,000 kilometers in radius.
Sharp edges in the meteorite suggest it formed near that body's surface, implying a radius of up to 1,800 kilometers—roughly lunar scale and potentially approaching Mars-sized in overall class.
The finding challenges the long-held view that low-silica angrites came from small asteroids and instead points to a distinct early planetary formation pathway 4.56 billion years ago.
Researchers say the destroyed embryo may have shattered in a collision, with some fragments possibly later incorporated into terrestrial planets including Earth.

Sources

Livescience.com3d ago

NWA 12774 Meteorite Study Reveals Evidence of Lost Moon- or Mars-Sized Protoplanet

Universe Today1d ago

A Rare Meteorite Just Revealed a Lost, Mars-Sized Planet from the Dawn of the Solar System - Universe Today

Yahoo! Voices3d ago

Rare meteorite might be a relic from a 'lost world'

10 Sources

Could fragments from this shattered protoplanet be the building blocks of worlds we know today, including Earth?

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NWA 12774: Evidence of a Massive Lost Protoplanet Reshapes Early Solar System History

Overview

NWA 12774 is a rare angrite meteorite found in the Sahara Desert, Northwest Africa. Its arrival on Earth has given scientists a unique window into the early solar system. By studying NWA 12774 and its preserved clues, researchers discovered compelling evidence of a massive, lost protoplanet that once existed. This meteorite reveals that early planet development followed different pathways than previously thought. The discovery of NWA 12774 has fundamentally changed our understanding of how planets formed, showing that the building blocks of the solar system were more diverse and complex than once imagined.

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