They shoot into the universe in all directions. Left, right, up, down, north, and south. At the highest speed possible in nature: 300,000 kilometers a second. Photons from the Sun can cover the distance to the Earth in just over 8 minutes. Five and a half hours later they pass the orbit of Pluto on their way to the stars. They have been doing it for 5 billion years, and they will continue to do so for another 5 billion.