Light has been in space for the entire duration of the existence of the universe. Since the Big Bang approximately 13.8 billion years ago, light has been traveling through space. As soon as the first atoms formed after the initial hot, dense phase of the universe, light was able to propagate through space. This early light is known as the cosmic microwave background radiation, and it permeates the entire universe. It provides valuable insights into the early stages of the universe's evolution. Since then, light from various sources such as stars, galaxies, and other celestial objects has been continuously traveling through space, allowing us to observe and study the universe.