When did Earth form and what was its initial state?
Earth formed approximately 4.54 billion years ago from the swirling debris of the solar nebula. The planet began as a violent, molten sphere of rock and metal with a liquid magma ocean surface.
Common questions about History of Earth
Short answers, pulled from the story.
How did the Moon form and when did it happen?
The Moon formed when a Mars-sized body named Theia collided with the proto-Earth. This giant impact hypothesis event ejected material into orbit that eventually coalesced to form the Moon.
When did the earliest evidence of life appear on Earth?
The earliest evidence of life dates back to at least 3.5 billion years ago. Fossilized microbial mats known as stromatolites found in Western Australia provide this evidence.
What caused the Snowball Earth ice ages and when did they occur?
The most severe Snowball Earth ice ages took place between 750 and 580 million years ago during the Proterozoic eon. Theories suggest the formation of the supercontinent Rodinia led to increased chemical weathering that removed carbon dioxide from the atmosphere.
When did the Cretaceous-Paleogene extinction event occur and what caused it?
The Cretaceous-Paleogene extinction event occurred at the end of the Mesozoic era and wiped out the non-avian dinosaurs. The cause is widely believed to be an asteroid impact that created the Chicxulub crater in the Yucatán Peninsula.
When did the human lineage diverge from the common ancestor of humans and chimpanzees?
The divergence of the human lineage from the common ancestor of humans and chimpanzees began around 6 million years ago. The first hominids were small, arboreal primates that lived in the forests of Africa.