Oxygen is often seen as a symbol of life, but its role deserves closer examination. Why do so many living beings depend on it ...

Galaxies typically begin from huge gas clouds that collapse and rotate ... As stars evolve over time, they create heavier elements such as oxygen and metals, which disperse throughout the galaxy ...

Liquid oxygen tank. Usually, oxygen is a gas. But at lower temperatures, it becomes a liquid. It takes up less space than gas, so you can store a lot more liquid oxygen in a thermos-like tank.