Did life exist before Earth? Harvard scientists find evidence in meteorites
Meteorites preserved the building blocks of life (photo: Pexels)
The components needed for life to emerge on Earth may be older than the planet itself — they formed before Earth was born, in the darkness of the early Solar System. Harvard scientists proved this by analyzing the composition of several meteorites, according to Interesting Engineering.
Where did the first molecules needed for life on Earth come from?
For a long time, scientists have been trying to determine the origin of complex organic compounds, including amino acids, found inside carbonaceous chondrites.
These rare rocky meteorites, more than 4.5 billion years old, formed directly from the protoplanetary dust cloud and contain tiny mineral spheres known as chondrules.
The key question was where exactly these organic molecules formed: deep in outer space or later under the influence of heating and chemical processes inside their parent asteroids.
What did the chemical analysis of space rocks actually reveal?
A team led by Daniel Crocker and David Johnston studied a diverse collection of primitive CI, CM and CR meteorites, as well as rare Bells and Tarda samples.
Precise measurements revealed that the oxygen isotopes in the organic matter of these objects have a clear primordial signature.
This indicator records the initial process of material mixing in the gas-and-dust disk long before the first planets appeared. This distribution proves that the molecules acquired their oxygen during the earliest stages of the Solar System’s existence.
A cross-section of the interior of a carbonaceous chondrite meteorite containing organic matter from the early Solar System (source: Harvard University, Cambridge, MA)
How did meteorites preserve the building blocks of life for billions of years?
Despite asteroids undergoing powerful collisions, internal heating, and exposure to melting water over billions of years, the chemical markers discovered remained virtually untouched.
This suggests that organic matter formed in the cold outskirts of the young Solar System, mixed in space, and later became part of meteorites.
Eventually, these space bodies delivered ready-made building blocks for the further development of biological life when they fell to the young Earth.
