National Geographic : 1990 Aug
Uranus DAY WAS BREAKING across Uranus as Voyager 2 looked back in 1986 at a planet tipped on its side, probably by a colossal primordial colli sion. Uranus receives only one-fourth the sun light Saturn does and hides its atmospheric features beneath a deep layer of hydrogen; the geology of its stunning moons stole the show. Neptune AGITATED despite the cold of minus 200°C, Neptune in 1989 showed Voyager storms like those on much warmer Jupiter. False color enhances a transparent haze, creating a red rim. White clouds and a circular storm form as convection shoots hydrocarbon gases up into colder regions, where they condense into bright ices. As with Jupiter and Saturn, internal heat drives Neptune's turbulence.