Our transcription: The young Earth was an irregularly shaped ball of rock adrift in space.
As meteorites were pulled into the planet by gravity, it grew larger and gradually acquired a spherical shape.
At the same time, a layered structure began to evolve.
No one knows how long it took for Earth to differentiate into its present structure.
Some of the oldest known terrestrial rocks resemble rock types forming today, suggesting that Earth's layering had begun to develop within the first half billion years of the planet's history.
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