Extreme Seasons Observed

Uranus's sideways tilt gives it the most extreme seasons of any planet, with each pole bathed in decades of unbroken sunlight and then decades of darkness. When Voyager 2 arrived in 1986, the south pole was pointing almost straight at the Sun.

Even with so little sunlight, Uranus's atmosphere is surprisingly active. In 2014, astronomers watched massive storms flare up in its northern hemisphere as spring took hold. How a planet this cold and distant drives such weather remains an open question.