Final answer:
Uranus has a unique rotation with a 98° tilt, resulting in dramatic seasons that last for 21 years each. The planet orbits on its side, causing alternating periods of sunlight and darkness. The behavior of Uranus' atmosphere during these seasons is complex and not fully understood.
Step-by-step explanation:
Uranus has a unique rotation because its spin axis is tilted by 98° with respect to the north direction. This means that Uranus orbits on its side, causing its seasons to be dramatically different from other planets. The tilt creates alternating periods of sunlight and darkness that last for 21 years each, with the Sun shining directly on one hemisphere while the other experiences darkness. The behavior of Uranus' atmosphere during these seasons is complex and not fully understood, but Voyager measurements show that the atmospheric temperature is even higher on the dark winter side than on the hemisphere facing the Sun.