The Speed of Light

Light moves about 186,000 miles per second (300,000 kilometers per second) when traveling through the vacuum of space. It can travel all the way from the sun to Earth—about 93 million miles (150 million km)—in about eight minutes.

If you completed the Traveling Light activity, you also know that light travels in a straight line. When light comes into contact with other objects (or even air), the direction and speed of the light can change. The speed does not change very much, and it is still very, very fast. Keep moving through the lesson to learn what happens when light comes into contact with other things.