🌌 Universe

Facts About the Universe: A Scale That Breaks the Brain

The observable universe is 93 billion light-years across and expanding. Most of what's in it is invisible, and most of what's visible is dying.

30 FactsVerifiedA FactFacts Post

There are roughly two trillion galaxies in the observable universe. Each contains anywhere from millions to trillions of stars. The numbers don't really land until you accept that they're never going to land.

About 95% of the universe is dark matter and dark energy — meaning we can detect its gravitational effects but have no idea what it actually is. The remaining 5% is everything we can see: galaxies, stars, planets, you.

The verified facts below cover cosmic scale, the structure of space-time, expansion, the cosmic microwave background, and the strange places where physics stops making sense.

Below: every fact from our verified archive that touches this topic. Each is independently sourced; click through to its dedicated page.

01
Space

Neutron stars are among the densest objects in the universe.

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02
Space

The Milky Way is just one of billions of galaxies in the universe.

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03
Space

The telescope expanded understanding of the universe.

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04
Science

Dark matter is believed to make up most of the universe’s mass but has not been directly observed.

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05
Space

Dark energy is thought to drive the accelerating expansion of the universe.

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06
Space

Gamma-ray bursts are among the most energetic events observed in the universe.

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07
History

The expansion of the universe was first observed in the 1920s.

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08
Space

The universe is estimated to be about 13.8 billion years old.

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09
Space

There are more stars in the universe than grains of sand on Earth.

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10
Space

The universe has no center.

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11
Space

The light you see from some stars today began traveling before humans existed.

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12
Space

The universe is so large that light from most of it will never reach Earth.

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13
Space

The universe may continue expanding forever.

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14
Science

There are particles older than the solar system.

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15
Science

There are unseen forces shaping the universe.

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16
Space

There are structures larger than galaxies.

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17
Space

The light from the most distant galaxies we see today left them before Earth even existed.

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18
Space

There are parts of the universe so far away that their light will never reach Earth, no matter how long we wait.

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19
Space

There are galaxies that formed shortly after the universe began.

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20
Space

The universe contains billions of galaxies.

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21
Space

The universe is expanding.

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22
Space

The universe has structure.

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23
Space

Some neutron stars rotate more than 600 times per second, making them the fastest spinning known objects in the universe.

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24
Space

There are stars whose light began its journey toward Earth before the Sun even formed.

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25
Science

The coldest known place in the universe is a laboratory on Earth that reached within a fraction of a degree of absolute zero.

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26
Space

There are particles from distant supernova explosions passing through your body right now.

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27
Space

The universe is estimated to be about 13.8 billion years old.

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28
Science

The atoms in your body will likely exist long after the Earth is gone.

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29
Space

There are galaxies so distant that their light has been traveling for over 13 billion years to reach Earth.

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30
Science

There are more possible games of chess than seconds in the age of the universe.

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