A Rare Meteorite Found in the Sahara Desert Offers Evidence of a Lost Protoplanet

Chemical signatures indicate the meteorite came from an early planet that met an untimely end during the formation of our solar system

Sara Hashemi | Daily Correspondent

June 11, 2026 8:00 a.m.

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A 4.5-billion-year-old meteorite found in the Sahara Desert could be evidence for a long-lost planet that never came to be.

The space rock, known as NWA 12774, was discovered in 2019 and belongs to a rare class of meteorites known as angrites. An analysis of its chemical composition suggests the object formed under deep pressure on a massive protoplanet that broke apart long ago, in the early era of our solar system. The findings were recently published in the journal Earth and Planetary Science Letters.

“Meteorites are essentially a library of information about the formation and evolution of the early solar system,” explains Aaron S. Bell, a study co-author and Earth scientist at the University of Colorado Boulder, to Gayoung Lee at Gizmodo. “Angrites, in particular, preserve a record of processes that occurred at the very beginning of planetary formation.”

Out of the roughly 80,000 meteorites discovered on Earth, just 68 of them are angrites, making these rare objects especially valuable as windows into the past. Angrites contain extremely low levels of silica, a major ingredient of almost every terrestrial planet in our solar system, which is why scientists assumed they must have come from asteroids.

But NWA 12774 challenged that idea—the researchers identified clinopyroxene, a mineral crystal commonly found in the Earth’s crust and mantle. The space rock’s clinopyroxene was also strangely rich in aluminum, a sign that the crystals formed under immense pressure.

Bell and his team devised a method to calculate how much pressure was needed to create such crystals. They spent about a year developing and testing a computer model that could reconstruct the conditions of the parent body that produced the meteorite.

They found that NWA 12774 would have needed at least 17.5 kilobars of pressure to form—meanwhile, the pressure at the bottom of the Mariana Trench, the deepest point on Earth, is just one kilobar. Essentially, the pressure required to make this meteorite was much higher than what could exist within a small asteroid.

The meteorite’s parent body must have been at least 1,200 miles across, according to the team’s calculations. But it could have been even larger—the crystals inside NWA 12774 are too sharp-edged to have survived deep underground, suggesting the rock formed nearer to the surface of its parent body. That would mean the world could have been closer in size to Earth’s moon, stretching at least 2,200 miles in diameter, and potentially even nearing the size of Mars, which is about 4,200 miles across.

“This means that, within four million years [of the solar system’s formation], you’re making things that are the size of the moon,” says Francois Tissot, a geochemist at the California Institute of Technology who was not involved in the work, to Jenna Ahart at Scientific American. “It’s a very, very rapid formation timescale.”

Overall, “it’s a very sound study,” adds Carl Agee, a meteoritics researcher at the University of New Mexico who wasn’t involved in the study, to the outlet. “I don’t think we’re at the point where we’ve proven beyond a shadow of a doubt that there was a very large early planet or body in the solar system that had these pressures. But this one particular angrite seems to be consistent with that idea.”

The scientists still don’t know how the protoplanet met its end. It’s possible that it was shattered during collisions in the early solar system, and its fragments later became part of Earth and other rocky planets, per a statement.

Regardless, the work indicates that scientists have a lot to learn from taking a closer look at meteorites, even those that have already been found. “There are many meteorites sitting in drawers that haven’t been thoroughly studied, so there were likely more of these protoplanets we don’t know about,” Bell says in the statement.

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Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.