Uploaded August 2026 | Updated September 2026, 3 weeks ago
Earth is just one planet in one solar system in one galaxy inside the whole of the universe. How long has this universe existed, anyway?
We asked Britannica editor Erik Gregersen to explain.
The universe is the whole cosmic system of matter and energy of which Earth—and therefore the human race—is a part. Today, we know that Earth is only a small ball of rock in a space of unimaginable vastness and that the birth of the solar system was probably only one event among many that occurred against the backdrop of an already mature universe.
This humbling lesson has unveiled a remarkable fact that endows even the minutest particle in the universe with a rich and noble heritage: events that occurred in the first few minutes of the creation of the universe 13.8 billion years ago turn out to have had a profound influence on the birth, life, and death of galaxies, stars, and planets.
Learn more from Britannica:
How fast is the universe expanding? britannica.com/story/how-fast-is-the-universe-expanding
What color is the universe? britannica.com/science/What-Color-Is-the-Universe
Was the Big Bang actually an explosion? britannica.com/story/was-the-big-bang-actually-an-explosion
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#EncyclopaediaBritannica
Inspiring curiosity and the joy of learning since 1768.
Web: britannica.com
Facebook: facebook.com/Britannica
Twitter: twitter.com/Britannica
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Earth is just one planet in one solar system in one galaxy inside the whole of the universe. How long has this universe existed, anyway?
We asked Britannica editor Erik Gregersen to explain.
The universe is the whole cosmic system of matter and energy of which Earth—and therefore the human race—is a part. Today, we know that Earth is only a small ball of rock in a space of unimaginable vastness and that the birth of the solar system was probably only one event among many that occurred against the backdrop of an already mature universe.
This humbling lesson has unveiled a remarkable fact that endows even the minutest particle in the universe with a rich and noble heritage: events that occurred in the first few minutes of the creation of the universe 13.8 billion years ago turn out to have had a profound influence on the birth, life, and death of galaxies, stars, and planets.
Learn more from Britannica:
How fast is the universe expanding? britannica.com/story/how-fast-is-the-universe-expanding
What color is the universe? britannica.com/science/What-Color-Is-the-Universe
Was the Big Bang actually an explosion? britannica.com/story/was-the-big-bang-actually-an-explosion
~~~
#EncyclopaediaBritannica
Inspiring curiosity and the joy of learning since 1768.
Web: britannica.com
Facebook: facebook.com/Britannica
Twitter: twitter.com/Britannica
Instagram: instagram.com/Britannica
