Where did it all begin?
The Big-Bang Theory: The creation of our universe occurred approximately thirteen billion years ago when it was very, very hot. It began with the explosion of concentrated matter and energy. Any matter in the area reacted with each other because of the extreme heat and an explosion occurred.
The fastest moving matter and energy traveled the farthest . The universe has been expanding ever since.
After the initial big bang, the force of gravity began to affect the matter.
Gravity is the force of attraction between any two objects. The more massive the object is, the stronger its gravitational attraction.
The force of gravity began to pull matter into clumps. The clumps formed huge clusters of matter. These clumps became the galaxies and the planets of the universe. The gravity of each planet keeps the planets in their particular orbit.
An Orbit is the path that an object takes as it travels.
About 13 billion years ago, the universe began as a tiny, dense, cluster of matter and energy that exploded.
In the early years, everything was made of gas. This gas, mostly hydrogen and helium expanded and cooled.
Over billions of years gravity caused gas and dust to form galaxies, stars, planets, and more.
The matter that spread out from the Big Bang developed into everything in the universe.
Two theories on the Universe:
Open Universe : The universe will continue to expand outward, until all the stars die out…billions of years from now.
Closed Universe : Gravity between the galaxies will cause the expansion outward to slow down and finally stop. Eventually gravity will pull the galaxies back toward the center. This will continue until all matter becomes again concentrated causing another big bang!
Order of the Universe – the big picture – Our Cosmic Address
Universe : The Universe was created 13 billion years ago from the Big Bang. Our universe contains thousands of Superclusters .
Supercluster : A supercluster is a system of many galaxies. We belong to the Virgo Supercluster .
Galaxy: Every galaxy contains billions of stars. Our galaxy is the Milky Way . Many planets, moons, asteroids and such orbit each of the stars. These are called solar systems.
Solar System: The sun is the star of our solar system. All of our planets orbit the sun.
Planet Earth: Planet Earth is our home planet. It is the ground beneath your feet!