A tiny meteorite has dramatically altered our understanding of how the planets in our solar system came into existence.

Scrutiny of shavings from the meteorite known as Northwest Africa 12264—a 50-gram (1.8 ounces) fragment believed to originate from the outer solar system—offers compelling evidence suggesting that rocky planets like Earth and distant icy bodies formed simultaneously. This groundbreaking find disputes the long-held notion that planets closer to the sun developed before those in the colder outer regions.

The Old Paradigm: A New Perspective?

Traditionally, scientists believed that the inner rocky planets—Mercury, Venus, Earth, and Mars—came into being approximately 4.566 billion years ago, with the gas giants and icy bodies emerging a tad later, around 4.563 billion years ago. This timeline stemmed from the assumption that cooler temperatures at greater distances from the sun delayed the formation of outer planets.

Moreover, the belief that water-rich rocky planets farther out accumulated more slowly due to extended heating processes further reinforced the classic theory.

Groundbreaking Analysis of the Meteorite

However, detailed analysis of the composition of Northwest Africa 12264, obtained from a Moroccan dealer in 2018, disclosed specific ratios of chromium and oxygen indicating its origin from the solar system's outer regions. Cutting-edge isotopic dating revealed that this space rock formed about 4.564 billion years ago—only 2 to 3 million years after the very first solid materials of the solar system.

Previously, such early formation was only attributed to bodies within the inner solar system.

A Paradigm Shift in Planetary Formation?

This revelation that rocky bodies beyond Jupiter formed rapidly—similarly to their inner-world counterparts—could revolutionize our understanding of planetary formation not just in our solar system, but potentially across galaxies. Researchers are optimistic that this exciting discovery hints at a more complex and dynamic process behind the birth of planets throughout the universe.