Time and Space Begin

Time Before Earth

The Beginning of the Universe

13.7 to 4.6

Billion Years Ago

The Big Bang:

Time began 13.7 billion years ago

Physicists estimate that time and space began 13.7 billion years ago, when, in less than 3 minutes, 98% of all matter that exists today exploded in a great fireball into the space it created as it inflated from an unimaginably intense concentration of energy smaller than a dot.

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The Big Bang

The First Atoms:

Simple atoms were formed 13.6 billion years ago

For 300,000 years after the Big Bang, the Universe was filled with radiation and minute particles, and was intensely hot. As the Universe expanded it cooled enough for opposing electrical charges to attract each other to form simple atoms. When all the electrons were attached in simple atoms, primal radiation began to spread throughout space.

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Atoms

Clusters and Galaxies:

Clusters and galaxies gathered 13.5 billion years ago

As the hydrogen and helium gas formed, it expanded and, under the force of gravity, gathered into billions of great clouds. These clouds formed into huge clusters with gigantic empty spaces in between. Gradually galaxies coalesced, forming groups within the clusters. It is the time when the Milky Way first began.

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Galaxies

Stars Light Up:

Stars appeared 13.4 billion years ago

Stars appeared between 200 and 900 million years after the Big Bang and new stars have continued to form and light our universe ever since. But stars do more than twinkle. Each of us is quite literally made of star dust from explosions at least 5 million years ago. If it weren't for the stars we would not be here.

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Stars

Our Sun and Planets Get Going:

Our solar system began 4.56 billion years ago

9 billion years after the Big Bang, our solar system began in an unusually dense swirl of star dust when one of the spiral arms of the Milky Way collapsed under the weight of gravity. 99.9 percent of the swirl eventually became the sun. The leftover .1 percent went into the planets and other objects in the sun's orbit.

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The Solar System

Purchase The Big Bang to Now: A Time Line

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Go to the next stop on the journey or return

Except for the background photographs of the Ghost Head nebulae and the cluster which are public domain images from NASA's archives.