Meteorite from the Mauritanian desert: Discovery of a moon-sized world that disappeared 4.5 billion years ago

Written by Omnia Hassan

In an exciting scientific discovery that could change scientists' understanding of the early stages of the formation of the solar system, a recent study has revealed strong evidence indicating the existence of a giant world the size of the moon, and perhaps close in size to Mars, before it disappeared following a catastrophic collision that occurred about 4.5 billion years ago.

A tiny rock reveals a colossal cosmic mystery

Surprisingly, the evidence for this lost world did not come from advanced telescopes or distant space missions, but from a meteorite found in the Sahara Desert.  Mauritania .

The meteorite is named “North West Africa 12774” (NWA 12774) and belongs to a very rare class of meteorites known as “angrites”, of which only 68 specimens have been discovered out of more than 80,000 known meteorites on Earth.

A mysterious structure that has puzzled scientists for decades

Angrite meteorites are among the oldest volcanic rocks in the solar system, having formed shortly after its birth about 4.56 billion years ago. They have attracted the attention of scientists because of their extreme lack of silica, an essential element in the formation of most rocky planets such as Earth and Mars.

For years, researchers have assumed these meteorites originated from small asteroids. But a new study led by a team from the University of Colorado Boulder has overturned this hypothesis.

Immense pressure reveals the size of the mother's body

Researchers found aluminum-rich crystals of the mineral “clinoperoxene” inside the meteorite. These crystals can only form under enormous pressures, and calculations showed that their formation requires a pressure of at least 17.5 kilobars, a level many times greater than the pressure at the deepest point in Earth’s oceans.

These results led scientists to conclude that the parent body from which these rocks originated was much larger than any known asteroid, estimating its radius to have exceeded 1,800 kilometers, making it close to the size of the moon and possibly a rival to Mars in some estimates.

A lost world that contributed to the building of the current planets

Researchers believe this protoplanet suffered a devastating collision during the early stages of the solar system's formation, breaking apart into fragments that scattered into space. Scientists believe some of these fragments may have later coalesced to form other planets, including Earth.

The research team asserts that the chemical composition of this lost world differs fundamentally from the components of Earth and Mars, indicating multiple and diverse paths for planet formation in the early solar system, and giving scientists a new window to understanding the history of the early universe and its lost secrets.