🪐 A Rare Meteorite May Preserve Evidence of a Lost World from the Dawn of the Solar System

Scientists at the University of Colorado Boulder have uncovered what may be the strongest evidence yet for a vanished protoplanet — a planetary embryo that once orbited the young Sun more than 4.5 billion years ago before being destroyed in a catastrophic collision.

The clue comes from an unusual meteorite known as Northwest Africa (NWA) 12774, discovered in the Sahara Desert. It belongs to the angrites, one of the rarest meteorite groups ever found. Out of more than 80,000 known meteorites, only a few dozen are classified as angrites. These rocks formed during the earliest stages of solar system history, just a few million years after the Sun was born.

What makes NWA 12774 remarkable is its mineral chemistry. Researchers found clinopyroxene crystals enriched in aluminum — a signature that indicates formation under enormous pressure. Their calculations suggest pressures exceeding 17.5 kilobars, more than 17 times greater than the pressure at the bottom of the Mariana Trench.

Such conditions could not have existed inside a small asteroid.

The results imply that the meteorite’s parent body had a radius of at least 1,000 km. Because the crystals preserve delicate structures that would likely not survive deep burial, the original world may have been much larger — potentially approaching the size of the Moon and perhaps even Mars.

🔹 Evidence points to a planetary embryo at least 1,000 km in radius
🔹 Formation pressures exceeded 17.5 kilobars
🔹 Its composition differs significantly from Earth and Mars
🔹 It may represent a previously unknown pathway of planetary evolution
🔹 Fragments of similar lost worlds could still be hiding in meteorite collections

The study suggests that the early solar system was far more diverse than previously thought. Many planetary embryos likely formed, collided, merged, or were destroyed before the planets we know today emerged.

How many lost worlds helped build the solar system we live in?

📄 Original paper (Earth and Planetary Science Letters) · ScienceDaily

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