Stephen Hawking - Formation of the Solar System

The Milky Way and Our Solar System's Origin00:00:02

Our solar system is located about 26,000 light-years from the center of the Milky Way galaxy. The story of its formation spans six billion years, starting with the explosion of an ancient star. This event scattered swirling clouds of materials and heavier metals, which we observe today as nebulae.

Formation of Planets from Nebulae00:01:03

Nebulae, formed from the remnants of exploded stars, contain all the necessary elements like nitrogen, oxygen, iron, and silica to build a world. Gravity then began to pull these materials together, leading to the formation of vast spirals of dust. At the center of one such spiral, Earth, built from stardust and assembled by gravity, began to take shape over 100 million years, sweeping up billions of tons of celestial debris.

Birth of Our Sun00:02:30

For Earth to evolve beyond a sterile rock, another crucial event was needed. Millions of miles away, at the heart of a giant nebula, the extreme pressure and temperature of a hydrogen gas ball caused atoms to fuse, igniting our sun. This new star gave off a huge blast of solar wind, sweeping remaining dust and gas to the outer edges of the solar system.

Structure of the Solar System and the Sun's Role00:03:41

This solar wind explains why the outer solar system contains huge gas planets like Jupiter, Saturn, Uranus, and Neptune, while the inner system holds denser, rockier planets such as Mercury, Venus, Mars, and Earth. The sun, with its massive diameter of 865,000 miles, will burn consistently for eight billion years, providing enough time for life to develop on Earth.