“Of all the planets, moons, asteroids, and comets in our Solar System, there is fire only on Earth – because there are large amounts of oxygen gas, O2, only on Earth. Fire was, much later, to have profound consequences for life and intelligence. One thing leads to another.”

“Of all the planets, moons, asteroids, and comets in our Solar System, there is fire only on Earth – because there are large amounts of oxygen gas, O2, only on Earth. Fire was, much later, to have profound consequences for life and intelligence. One thing leads to another.”

— Carl Sagan