The Sun

— Alex Green

“For thousands of years, it was an article of faith that the world was an immovable disk around which the sun, the planets and the stars all revolved. Everyone believed, indeed knew this.

That changed a few centuries ago. Yet it is only within the last few decades – using everything from ground-based telescopes and spectroscopes to the space-based Solar and Heliospheric Observatory – that we have gained a real understanding of our nearest star.

It is 93 million miles away. A passenger jet flying 550 miles per hour would take 20 years to get there. To reach the next nearest star, Alpha Centauri, that same plane would need 5 million years.

The sun is by far the largest object in our neighborhood, making up 99.8% of the mass of the solar system. Its diameter is 865,000 miles. Were it hollow, 1.3 million Earths could fit inside it. Yet, in astronomical terms, the sun is just an average-sized gas ball – out of some 200 billion – in the Milky Way galaxy.”