We've learned a lot about Earth's atmosphere and climate by studying other planets. As the American Institute of Physics writes: "In the 1960s and 1970s, observations of Mars and Venus showed that planets that seemed much like the Earth could have frightfully different atmospheres. The greenhouse effect had made Venus a furnace, while lack of atmosphere had locked Mars in a deep freeze. This was visible evidence that climate can be delicately balanced, so that a planet's atmosphere could flip from a livable state to a deadly one."
The photo above was taken over Saturn's north pole by NASA's Cassini orbiter on November 27, 2012 from a distance of 376,171 kilometers (233,742 miles). It shows a very interesting and intriguing atmospheric phenomenon that we haven't seen anywhere else.