Light from the Sun takes about eight minutes to reach our planet.

The longer version

Sunlight crossing the gap between the Sun and Earth takes about eight minutes, so we never see the Sun as it is right now. We see it as it was when the light left. The same delay applies to the reach of its gravity in principle, and to any signal sent outward.

This delay sets a natural scale for the solar system. Neptune sits so far out that sunlight there arrives hours after leaving the Sun, and its light is far dimmer. Astronomers use light travel time as a yardstick, which is why the light-year exists as a unit of distance.

Where this entry sits

The night sky looks calm, yet almost everything up there is moving, burning, or slowly changing. These facts cover planets, stars, the Moon, gravity, black holes, comets, and the story of how people began exploring beyond Earth. The full list sits on the Space and Sky page, where every entry is listed in order.