Earth formed about 4.6 billion years ago, during the geological eon known as the Hadean. The name “Hadean” comes from the Greek god of the underworld, reflecting the extreme heat that likely characterized the planet at the time.
By 4.35 billion years ago, the Earth might have cooled down enough for the first crust to form and life to emerge.
However, very little is known about this early chapter in Earth’s history, as rocks and minerals from that time are extremely rare. This lack of preserved geological records makes it difficult to reconstruct what the Earth looked like during the Hadean Eon, leaving many questions about its earliest evolution unanswered.