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The Question

(Submitted February 15, 1998)

How is a solar system such as ours created?

The Answer

A solar system is created when a rotating cloud of gas and dust in space start to coalesce - they are pulled together and towards the center of the gas/dust cloud by their gravitational attraction to each other. As they condense, the particles collide faster and more often, which causes the gas and dust to heat up. The gas and dust at the center collapses to form the central star of the solar system; the heat generated by the colliding particles starts nuclear fusion in its core. If there was enough angular momentum in the system at the very beginning, then not all of the dust and gas will go into the central star - the rest will remain in a flattened disk around the star. The planets form from this disk of rotating material as it clumps together because of gravity.

There are a number of places on the web where you can go to for a more detailed description of the process, and even some numerical simulations of this.

J. Allie Hajian
for Ask an Astrophysicist

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