太阳系是如何形成的

The Universe: How the Solar System was Made

At 4.6 billion years old, the Solar System is our solid, secure home in the Universe. But how did it come to be? In this episode we trace the system's birth from a thin cloud of dust and gas. Shocked by a nearby supernova, the pull of gravity and natural rotation spun it into a flat disc from which the Sun and planets coalesced. It all happened in the space of 700 million years, during which the planets jockeyed for position, dodging the brutal bombardment of deadly asteroids and setting into the neat, stable system that we now realize might be a rarity in the universe.