The Big Bang
The universe begins as a extremely hot, dense point and rapidly expands.
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Artist's Impression of the Big Bang
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A Model of a Quark
Formation of Fundamental Particles
Quarks, electrons, and neutrinos form as the universe cools.
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A Model of an Atom
First Atoms
Hydrogen and helium atoms form, allowing light to travel freely.
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An Artist's Impression of one of the First Stars to Form
First Stars Ignite
Gravity pulls gas together, igniting the first generation of stars.
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Early Galaxies that Formed
Galaxies Form
Stars cluster into galaxies, including early versions of the Milky Way.
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How our Solar System was Forming
Our Solar System Forms
The Sun and planets form from a collapsing cloud of gas and dust.
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What Scientists Think Were the First Living Things on Earth
First Life on Earth
Simple life emerges in Earth's oceans.
Present
An Image of the Observable Universe
Modern Universe
The universe continues to expand as humans study the cosmos.