A new infrared image from NASA’s Cassini orbiter shows enormous clouds in the northern hemisphere of the gas giant Saturn.
This false-color image from Cassini shows clouds in the atmosphere of Saturn. Image credit: NASA / JPL-Caltech / Space Science Institute / Kevin M. Gill.
This image was produced by Kevin M. Gill, an engineer at NASA’s Jet Propulsion Laboratory.
The view was made using images taken by Cassini’s wide-angle camera on July 20, 2016, using a combination of spectral filters sensitive to infrared light at 750, 727 and 619 nanometers.
The filters are sensitive to absorption and scattering of sunlight by methane in the atmosphere of Saturn.
They have been useful throughout Cassini’s mission for determining the structure and depth of cloud features in the planet’s atmosphere.
Saturn is about 75% hydrogen and 25% helium with traces of other substances like methane and water ice, according to planetary researchers at ESA.
The planet is one of the windiest places in the Solar System.
The wind blows at high speeds on Saturn due to more energy emitted from its core as compared to Jupiter. Near the equator, it reaches velocities of 1,120 mph (1,800 km per hour).
Saturn’s atmosphere is only a narrow region, compared to the vast interior of the gas giant.
There are three regions in the Saturn’s lower atmosphere (troposphere) where clouds of a particular kind, or ‘cloud decks,’ can be found.
The temperature in Saturn’s troposphere ranges from minus 202 degrees Fahrenheit to 176 degrees Fahrenheit (from minus 130 to 80 degrees Celsius).
The top visible cloud deck, made of ammonia clouds, is found at about 62 miles (100 km) below the top of the troposphere (tropopause), where the temperature is about minus 418 degrees Fahrenheit (minus 250 degrees Celsius).
The second cloud deck, made of ammonium hydrosulfide clouds, is found at about 105 miles (170 km) below the tropopause, where the temperature is minus 94 degrees Fahrenheit (minus 70 degrees Celsius).
The lowest cloud deck, made of water clouds, is found at about 80 miles (130 km) below the tropopause, where the temperature is about 32 degrees Fahrenheit (0 degrees Celsius).
The hydrogen gas that makes up most of the atmosphere slowly changes to liquid with depth as the pressure increases. Below the liquid hydrogen rests the heavier liquid helium.
Deep in the depths of the body of Saturn, the hydrogen is then under tremendous pressure, and is transformed to liquid metallic hydrogen.
