Saturn’s atmosphere exhibits a banded pattern similar to Jupiter’s, but Saturn’s bands are much fainter and are much wider near the equator. The nomenclature used to describe these bands is the same as on Jupiter. Saturn’s finer cloud patterns were not observed until the flybys of the Voyager spacecraft during the 1980s. Since then, Earth-based telescopy has improved to the point where regular observations can be made. The composition of the clouds varies with depth and increasing pressure.
The winds on Saturn are the second fastest among the Solar System’s planets, after Neptune’s. Voyager data indicate peak easterly winds of 500 m/s (1,800 km/h).
Thermography has shown that Saturn’s south pole has a warm polar vortex, the only known example of such a phenomenon in the Solar System. Whereas temperatures on Saturn are normally −185 °C, temperatures on the vortex often reach as high as −122 °C, suspected to be the warmest spot on Saturn.
Credit: NASA/JPL-Caltech/Space Science Institute and Kevin M. Gill
Enceladus and Saturn
Image credit: Gordan Ugarkovic
Observations of Earth, Soyuz, Aurora, moon and Space Shuttle Endeavor made from the International Space Station.
Jupiter is perpetually covered with clouds composed of ammonia crystals and possibly ammonium hydrosulfide. The clouds are located in the tropopause and are arranged into bands of different latitudes, known as tropical regions. These are sub-divided into lighter-hued zones and darker belts. The interactions of these conflicting circulation patterns cause storms and turbulence. Wind speeds of 100 m/s (360 km/h) are common in zonal jets. The zones have been observed to vary in width, color and intensity from year to year, but they have remained sufficiently stable for scientists to give them identifying designations.
The cloud layer is only about 50 km (31 mi) deep, and consists of at least two decks of clouds: a thick lower deck and a thin clearer region. There may also be a thin layer of water clouds underlying the ammonia layer. Supporting the idea of water clouds are the flashes of lightning detected in the atmosphere of Jupiter. These electrical discharges can be up to a thousand times as powerful as lightning on Earth. The water clouds are assumed to generate thunderstorms in the same way as terrestrial thunderstorms, driven by the heat rising from the interior.
This scene, captured with a 35mm camera from inside the Space Shuttle Endeavour, shows Jupiter rising above the airglow over Earth’s horizon. The crescent Moon is at top frame.
Citizen scientist Rick Lundh created this abstract Jovian artwork using data from the JunoCam imager on NASA’s Juno spacecraft.
Image credits: NASA/JPL-Caltech/SwRI/MSSS/Rick Lundh
Juno in Jupiter (the images that appear the juno probe is just an illustration) +Jupiter
Image credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill
Aurora Over Alaska
Credit: Joshua Strang, USAF, Wikipedia
Titan is primarily composed of water ice and rocky material. Much as with Venus before the Space Age, the dense opaque atmosphere prevented understanding of Titan’s surface until new information from the Cassini–Huygens mission in 2004, including the discovery of liquid hydrocarbon lakes in Titan’s polar regions. The geologically young surface is generally smooth, with few impact craters, although mountains and several possible cryovolcanoes have been found.
The atmosphere of Titan is largely nitrogen; minor components lead to the formation of methane and ethane clouds and nitrogen-rich organic smog. The climate—including wind and rain—creates surface features similar to those of Earth, such as dunes, rivers, lakes, seas (probably of liquid methane and ethane), and deltas, and is dominated by seasonal weather patterns as on Earth. With its liquids (both surface and subsurface) and robust nitrogen atmosphere, Titan’s methane cycle is analogous to Earth’s water cycle, at the much lower temperature of about 94 K (−179.2 °C).
Image credit: NASA/JPL/Kevin Gill
Images taken by the International Space Station (ISS)
credit: NASA (Expedition ISS)