This drawing illustrates "eccentricity". Click on image for full size version (40K GIF)

The Martian climate is more influenced by the shape of the Martian orbit than the climate of the Earth is influenced by the shape of the Earth's orbit. The orbit of Mars is more oval-shaped than that of the Earth. The difference between the oval shape of the Martian orbit and a perfect circle is called the *eccentricity* of the orbit.

Because the Martian orbit has large differences in the distance from the sun, the surface of Mars can experience larger changes in temperature than does the Earth.

Changes in the inclination of the axis of revolution of Mars is also much more extreme than that of the Earth. This means that differences between summer and winter of Mars can be more extreme than on Earth.

The high eccentricity of the Martian orbit, combined with the high inclination of the axis of revolution, means that, if conditions are just right, there are times when Mars can experience a great deal more warming than normal. These extremes in the warming of the surface of Mars means that Mars has more potential for climate change brought about by orbit conditions than does the Earth.