Speed of light: fast, but slow. The Moon is the closest celestial body to Earth, 239,000 miles (384,400 kilometers) from Earth. The photons emitted from Earth will be in just 1.

Speed of light: fast, but slow.

The Moon is the closest celestial body to Earth, 239,000 miles (384,400 kilometers) from Earth. Photons emitted from Earth will reach the moon in as little as 1.25 seconds.

The nearest approach to the celestial body when the distance from Earth travel time to the moon 0.38 million km 1.25 seconds Mars 54.6 million km 3 minutes Sun 150 million km 8 minutes Jupiter 588 million km 33 minutes Saturn 1.2 billion km 67 minutes Pluto 4.3 billion km 4 hours

If you look at the entire length of the video above, you might see how "slow" the light is. It took three minutes for the same photon to reach the moon in a little more than a second to reach Mars, the next planet outside of Earth in our solar system.

It only takes eight to get from the sun to the earth. This means that when we look at the sun, we see the sun eight minutes ago, and if it suddenly disappears, we will not realize it for a full eight minutes.

Therefore, the "fast" or "slow" of light depends on your point of view. For those of us who inhabit Earth, it feels like an instant. But the sheerness of the universe makes even light seem slow — it travels at a speed that our spacecraft isn't even close to matching.