NASA’s Voyager 2 spacecraft captured these views of Uranus (on the left) and Neptune (on the right) during its flybys of the planets in the 1980s. Credit: NASA/JPL-Caltech/B. Jónsson
Astronomers may now understand why the similar planets Uranus and Neptune are different colors. Using observations with the Gemini North telescope and NASA Infrared Telescope Facility on Maunakea, and the Hubble Space Telescope in orbit, researchers developed a single atmospheric model that matches observations of both planets. The model reveals that excess haze on Uranus builds up in the planet’s stagnant, sluggish atmosphere and makes it appear a lighter hue than Neptune.