It takes about 8 minutes and 20 seconds for sunlight to reach Earth.

The speed of light in a vacuum is a fundamental physical constant exactly defined as 299,792,458 meters per second. This speed is often rounded to 300,000 kilometers per second or 186,282 miles per second for general calculations. Because the Earth orbits the Sun in an elliptical path, the distance between the two bodies varies throughout the year.At its closest point, known as perihelion, the Sun is about 91.4 million miles away. At its farthest point, called aphelion, it sits roughly 94.5 million miles away. On average, the distance is 92.96 million miles, which astronomers define as one Astronomical Unit (AU). Dividing this average distance by the speed of light results in an average travel time of approximately 499 seconds.This delay means that our visual perception of the cosmos is always a look back in time. This phenomenon is not limited to our Sun, as the light from the next closest star, Proxima Centauri, takes over four years to reach us. NASA and other space agencies must account for these light-speed delays when communicating with deep-space probes like Voyager 1 or the Mars rovers.If the Sun were to theoretically disappear, the effect would not be instantaneous due to the limits of causality. According to Einstein's theory of general relativity, gravity also travels at the speed of light. Therefore, Earth would continue orbiting an empty spot in space for the same 8 minutes and 20 seconds before flying off into a straight line.