The Birth of the Solar System

What happened

About 4.6 billion years ago, a dense cloud of interstellar gas and dust — part of a larger nebula — collapsed, perhaps triggered by the shockwave of a nearby exploding star. It flattened into a spinning disk; at the center, gravity packed material together until hydrogen began to fuse, and the Sun was born, taking up more than 99% of the matter. The leftover disk clumped into planets, moons, and smaller bodies.

Why it matters

This ordinary event around one young star produced the Sun and its planets — including the Earth, the only place life is known to exist.

Sources

• NASA Space Place. How Did the Solar System Form? · Reputable source