Clouds on Neptune
An interesting feature on Neptune is the existence of high altitude clouds on the surface. The clouds are long and bright, much like the cirrus clouds on Earth and cast shadows on lower cloud decks. The clouds are usually 48 to 160 kilometers wide (30 to 100 miles wide) and extend for thousands of miles.
The Hubble Space Telescope also caught site of high altitude clouds, revealing much about Neptune's dynamic weather patterns. The clouds change at an extremely fast rate, evidence that Neptune's internal heat combustion plays a major role in interacting with the gasses of the planet.