Earth's orbit varies from nearly a circle to an ellipse and back again in about:
A) 1,000,000 years.
B) 100,000 years.
C) 10,000 years.
D) 1,000 years.
E) 100 years.

Question

Quizplus · Accepted Answer

The shape of Earth's orbit varies from nearly circular to more elliptical and back again in a cycle that takes about 100,000 years. This is known as the eccentricity cycle, which is one of the Milankovitch cycles that describe the collective effects of changes in the Earth's movements upon its climate.

Earth's Orbit Varies from Nearly a Circle to an Ellipse