Scientists Find Relic of Lost Moon-Sized Planet

Scientists have found evidence of a lost world hiding in plain sight inside a rare meteorite recovered from the Sahara Desert in 2019.

The ancient space rock, called NWA 12774, likely came from the depths of a massive protoplanet that existed when our solar system was just a toddler. Researchers at the University of Colorado Boulder discovered that crystals inside the meteorite formed under extreme pressure, meaning they could only have come from deep within a world at least 1,000 kilometers in radius.

That's roughly the size of Earth's moon. Some evidence even suggests the parent body could have been much larger, possibly approaching the size of Mars.

The meteorite belongs to an extremely rare class called angrites, ancient volcanic rocks that date back 4.56 billion years. Of the 80,000 meteorites ever cataloged on Earth, fewer than 70 are angrites.

Lead researcher Aaron Bell and his team made the discovery by examining aluminum-rich crystals in the meteorite. The high aluminum content was a "flashing red light" that something unusual was going on, Bell says.

They spent a year developing a new computational tool to calculate the pressure conditions where these crystals formed. The results showed pressures exceeding 250,000 pounds per square inch, more than 15 times what you'd feel at the deepest point of Earth's oceans.

Scientists had previously assumed angrites came from small asteroids. This finding completely changes that picture and proves that massive planetary bodies formed incredibly fast in our solar system's early days.

Why This Inspires

This discovery shows that even 4.56 billion years later, our solar system still has secrets to reveal. A world that was nearly as large as our moon existed, thrived, and disappeared before life even began on Earth, yet left behind tiny messengers that traveled across space and time to tell its story.

The lost protoplanet likely broke apart through collisions billions of years ago. Its fragments may have become part of the planets we walk on today, or scattered into the asteroid belt to rain down as meteorites across the ages.

What's especially remarkable is how quickly this massive world formed. Within just four million years of the solar system's birth, objects the size of moons were already taking shape, says Francois Tissot, a geochemistry researcher at Caltech who wasn't involved in the study.

The discovery opens new questions about planet formation and what other lost worlds might be hiding in meteorite collections around the globe. Every space rock that falls to Earth carries the potential to reveal another chapter of our cosmic history.

Scientists are now working to refine their models of early planet formation to understand how such massive bodies could have arisen and vanished so quickly. The atomic-scale clues locked inside these ancient crystals are helping them piece together the story of worlds that existed before our own.