Perihelion and aphelion pronunciation'

Earth-Sun distance shaves 15 minutes off summer in 2025

Changing Elliptical Orbit

The Earth orbits the Sun in an elliptical path, which means that there is one point on the path closest to the Sun and one point that is farthest away from the Sun.

Orbit Changes Shape

This path's shape varies due to the gravitational influences of other planetary objects, particularly the Moon.

Approximately every 100,000 years, the Earth's orbital path changes from being nearly circular to elliptical. The difference of the Earth’s orbital shape from a perfect circle is known as its eccentricity. An eccentricity value of 0 is a circular orbit, while values between 0 and 1 describe an elliptical orbit.