Scientists have uncovered exceptionally rare traces of “proto Earth,” the ancient version of our planet that existed about 4.5 billion years ago. This early Earth formed before a massive collision forever changed its makeup and created the world we know today. The results provide new insight into the original building materials that shaped Earth.

Billions of years ago, the solar system began as a swirling cloud of gas and dust. Over time, this material clumped together, forming the first meteorites. These early space rocks eventually merged to create the proto Earth and the other planets that orbit the Sun. During its earliest days, Earth was a molten, volcanic world. Less than 100 million years later, a Mars-sized object collided with it in a dramatic “giant impact.” The event erased almost all of the planet’s initial chemistry.