Space, often referred to as the final frontier, is a vast and seemingly infinite expanse that extends beyond Earth's atmosphere. It is characterized by the absence of air, allowing for the free movement of celestial bodies and electromagnetic radiation. The universe, of which space is a fundamental component, contains an estimated 100 billion galaxies, each comprising billions or even trillions of stars, as well as various other celestial objects such as planets, moons, asteroids, and comets.