Safekipedia
Astronomical dynamical systemsConcepts in astronomyEnvironmentsMain topic articles

Universe

Adapted from Wikipedia · Explorer experience

A stunning view of distant galaxies captured by the Hubble Space Telescope, showing how vast and beautiful our universe is.

The Universe

The universe is everything that exists. It includes all the stars, planets, galaxies, and even the tiny particles we can’t see. It also has space and time. Everything we know is a part of the universe.

Long ago, people thought Earth was the center of everything. Now we know that Earth moves around the Sun, which is just one star in the Milky Way. The Milky Way is a big collection of stars, and there are many other galaxies like it.

The universe began with something called the Big Bang about 13.8 billion years ago. It started very small and hot, and it has been growing ever since. Scientists study the universe to learn more about it. They use special tools like telescopes to look at faraway stars and galaxies.

The universe is mostly made of something we can’t see called dark matter and dark energy. Only a little part of the universe is made of the matter we can see, like stars and planets. Even though we can’t see dark matter or dark energy, we know they are there because of how they affect the things we can see.

People wonder if there is life somewhere else in the universe. Scientists look for answers by studying the stars and planets. The universe is a big and amazing place full of mysteries waiting to be discovered.

Images

The Crab Nebula is the remnant of a star that exploded long ago, creating beautiful glowing clouds of gas and dust in space.
A timeline showing how the universe has evolved over billions of years, from the Big Bang to today.
A stunning view of Earth from space, captured by astronauts during the Apollo 17 mission.
Cosmic microwave background radiation map showing temperature variations from the early universe.
A diagram showing the vast scale of the universe, with Earth at the center and distant galaxies and cosmic structures expanding outward.
A scientific visualization showing how galaxies and cosmic structures form over billions of years.
A map showing the distribution of empty spaces and large clusters of galaxies within 500 million light years of our Milky Way.
A diagram showing the masses and sizes of various objects in our universe, from tiny particles to massive stars and galaxies.
A 16th-century map showing the celestial spheres, an early model of the universe created by Thomas Digges.
A diagram showing the observable universe with stars, galaxies, and other space objects arranged by their distance from Earth.
A colorful and accurate diagram of our Solar System, showing planets, their moons, and dwarf planets arranged by their orbits.
An artistic representation of the geometry and structure of the Universe, showing how space might be understood through shapes and geodesics.
An ancient illustration showing how the Greek scientist Aristarchus calculated the sizes of the Sun, Moon, and Earth.

This article is a child-friendly adaptation of the Wikipedia article on Universe, available under CC BY-SA 4.0.

Images from Wikimedia Commons. Tap any image to view credits and license.