The Answer:

The average distance between the Sun and the Earth is about 92,935,700 miles. Astronomers refer to this distance as one astronomical unit—the distance light travels in about eight and a half minutes.

Earth's orbit is actually not perfectly circular; the distance between the Earth and the Sun varies slightly over the course of the year. This does not, however, account for seasons; the angle of the Earth's axis relative to the sun is responsible for that.

For more information, refer to the astronomical constants and basic planetary data pages in the Information Please Almanac.

—The Editors