Mars has the highest orbital eccentricity of any planet except Mercury and Pluto. Its distance from the Sun varies between 1.64 and 1.36 AU over the Martian year. This large variation, combined with an axial tilt greater than Earth's, gives rise to a very peculiar seasonal change. When Mars is closest to the Sun, it is wintertime at the planet's north pole. Mars's atmosphere is noticeably thinner during northern winter.
Martian seasons are peculiar by Earth-standards, but they pale in comparison to seasons on Uranus.
This dramatic time-lapse movie captured by NASA's Hubble Space Telescope shows seasonal changes on Uranus. Once considered one of the blander-looking planets, Uranus is now revealed as a dynamic world with the brightest clouds in the outer Solar System. The northern hemisphere of Uranus is just now coming out of the grip of its decades-long winter. Sunlight, reaching some latitudes for the first time in years, warms the atmosphere and triggers gigantic springtime storms comparable in size to North America with temperatures of 300 degrees below zero. In the animation pictured left, bright clouds are probably made of crystals of methane, which condense as warm bubbles of gas percolate upwards through the atmosphere.