How long does it take sunlight to reach Earth?

How long does it take sunlight to reach Earth? The answer is about 8 minutes and 20 seconds. Light travels through space at approximately 299,792 kilometers per second, and the average distance between Earth and the Sun is about 149.6 million kilometers. Dividing that distance by light’s speed gives roughly 499 seconds, or 8 minutes 19 seconds, commonly rounded to 8 minutes 20 seconds.

This delay means we never see the Sun exactly as it is at the present moment. Every view of the Sun shows it as it appeared a little more than eight minutes earlier. The same principle applies to sunlight warming Earth and powering photosynthesis: energy released at the Sun’s surface takes several minutes to arrive here.

The exact travel time varies slightly because Earth’s orbit is elliptical. Earth is closer to the Sun at perihelion and farther away at aphelion, so sunlight takes a little less or a little more than the average time. Sunlight reaches the Moon in about 1.3 seconds.