How does the eccentricity of Mars orbit affect the seasonal variations?
Earths orbit is very nearly circular, and so the four seasons last approximately the same number of days. The orbit of Mars, however, is a bit more eccentric (0.0934). In accordance with Keplers laws of orbital motion, Mars travels more slowly in its orbit when it is further from the sun, and more quickly when it is nearer to the sun. Mars reaches its furthest point from the sun (called “aphelion”) when it is spring in the northern hemisphere. This has the effect of making spring the longest season (193.30 sols), and summer the second longest (178.64 sols). Mars reaches its closest point to the sun (called “perihelion”) when it is autumn in the northern hemisphere, and consequently autumn is the shortest season (142.70 sols), and winter is the second shortest (153.94 sols). Take a look at this figure. Notice that on a calendar containing 24-months of equal duration, spring (green) contains seven months, while autumn (orange) contains a little more than five. Summer (yellow) has a littl
