Atmosphere of Uranus vast. The number density of atomic hydrogen in the corona falls slowly with the distance from the planet, remaining as high a few hundred atoms per cm at a few radii from Uranus. The effects of this bloated exosphere include a drag on small particles orbiting Uranus, causing a general depletion of dust in the Uranian rings. The infalling dust in turn contaminates the upper atmosphere of the planet. Uranus has a relatively bland appearance, lacking broad colorful bands and large clouds prevalent on Jupiter and Saturn. No discrete features were observed in Uranus's atmosphere before 1986. The most conspicuous
Elongation (astronomy) Elongation (astronomy) In astronomy, a planet's elongation is the angular separation between the Sun and the planet, with Earth as the reference point. The greatest elongation of a given inferior planet occurs when this planet’s position, in its orbital path around the Sun, is at tangent to the observer on Earth. Since an inferior planet is well within the area of Earth's orbit around the Sun, observation of its elongation should not pose that much a challenge (compared to deep-sky objects, for example). When a planet is at its greatest elongation, it appears farthest from the Sun as viewed from