How far is the Sun from Earth?

The average distance between Earth and the Sun is about 149.6 million kilometres, a unit astronomers call one astronomical unit (AU), officially defined in 2012 as exactly 149,597,870,700 metres. Sunlight takes about 8 minutes and 20 seconds to reach us. Because the orbit of Earth is slightly elliptical, we are closest to the Sun, about 147.1 million kilometres, in early January, and farthest, about 152.1 million kilometres, in early July. This small change is not what causes the seasons; the tilt of Earth does. In December 2024 NASA Parker Solar Probe flew within about 6.1 million kilometres of the solar surface, the closest any spacecraft has come.