A Universe of Winter
Each planet in the solar system has seasons determined by the tilt of its axis and the shape of its orbit, just like on Earth. Smaller tilts and more circular orbits correspond with less-noticeable seasons: On Venus and Jupiter, with minimal tilts and roundish orbits, summer and winter are pretty similar. On Mars, the tilt of 24 degrees and oval orbit give it dramatic seasonal shifts. Seasons on the solar system’s outer planets are not well understood, but scientists do know their winters last a lot longer than on Earth — about 7 years on Saturn, 20 years on Uranus, and more than 40 years on Neptune.