Earth forms
Gravity gathers a third planet from the Sun
Quick facts
- Earth formed
- About 4.5 billion years ago
- Position
- Third planet from the Sun
- Early state
- Molten and heavily bombarded, cooling over time
- Built from
- Gas and dust in the disk around the young Sun
What happened
As the young Solar System settled into its current layout about 4.5 billion years ago, gravity pulled swirling gas and dust in the disk around the Sun together into larger and larger clumps, and one of them became Earth, the third planet out. The early Earth was a violent, largely molten world, bombarded by leftover debris and far too hot for the oceans and continents we know. Over time it cooled, grew a solid crust, released gases that formed an early atmosphere, and eventually held liquid water.
Why it matters
Every human being who has ever lived, and every event on every human timeline the site holds, takes place on this one planet. Its formation is where the story stops being about the universe in general and starts being about home.
How we know
NASA's facts on Earth describe its formation as the Solar System settled into place about 4.5 billion years ago, when gravity pulled gas and dust together to build the planet.
Sources
- NASA. Earth: facts (NASA Science) (2024) · Reputable sourcescience.nasa.gov · The domain "science.nasa.gov" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- U.S. Geological Survey. Geologic Time: Age of the Earth (4.54 billion years) (U.S. Geological Survey) · Reputable sourcepubs.usgs.gov · The domain "pubs.usgs.gov" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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