Saturn Moon Has Oxygen Atmosphere An oxygen atmosphere has been found on Saturn's second largest moon, Rhea, astronomers announced Thursday—but don't hold your breath for colonization opportunities. For one thing, the 932-mile-wide (1,500-kilometer-wide), ice-covered moon is more than 932 million miles (1.5 billion kilometers) from Earth. For another, the average surface temperature is -292 degrees Fahrenheit (-180 degrees Celsius). And at less than 62 miles (100 kilometers) thick, the newfound oxygen layer is so thin that, at Earthlike temperatures and pressure, Rhea's entire atmosphere would fit in a single midsize building. Still, the discovery implies that worlds with oxygen-filled air may not be so unusual in the cosmos. (Related: "Potentially Habitable Planets Are Common, Study Says.") At about 327,000 miles (527,000 kilometers) from Saturn, Rhea orbits inside the planet's magnetic field. Knowing where and how oxygen exists in the universe may in turn help scientists plan future robotic and manned missions.
Sights and Sounds of Titan Sights and Sounds of Titan The European Space Agency's Huygens probe has landed on Saturn's giant moon Titan. Listen to this story via streaming audio, a downloadable file, or get help. January 16, 2005: Congratulations, ESA! The European Space Agency's (ESA's) Huygens probe, carried to Saturn by the Cassini spacecraft, parachuted to the surface of Saturn's giant moon Titan on Friday, Jan. 14th, revealing finally what lies beneath Titan's thick orange clouds. Right: From an altitude of 16 km, Huygens photographed these drainage channels leading to a shoreline. First images released by the ESA depict sinuous drainage channels leading to an apparent shoreline. It's all a bit familiar, yet at the same time utterly alien. Above: Small "rocks," possibly made of water ice, at the Huygens landing site. Because Titan has a thick atmosphere, able to carry sound waves, the moon is a noisy place. Huygens was designed to float in case it landed in a river or lake--but it didn't.
Enceladus Saturn II Enceladus ("en SEL a dus") is the eighth of Saturn's known satellites: orbit: 238,020 km from Saturn diameter: 498 km mass: 7.30e19 kg In Greek mythology Enceladus was a Titan who was defeated in battle and buried under Mount Etna by Athena. Discovered in 1789 by Herschel. Craters and smooth plains Enceladus has the highest albedo (>0.9) of any body in the solar system. At least five different types of terrain have been identified on Enceladus. This means that Enceladus must have been active until very recently (and perhaps is still active today). Enceladus is much too small to be heated solely by the decay of radioactive material in its interior at present. Cassini closeup view (looks like Europa?) Enceladus is locked in a 1:2 resonance with Dione (similar to the situation between Io and Europa). Enceladus is very likely the source of the material in Saturn's tenuous E ring. More about Enceladus Open Issues What is the resurfacing mechanism? Home ...
The Unsolved Mystery of Saturn's Hexagon -4 Times the Size of Earth "Cassini is indebted to Voyager for its many fascinating discoveries and for pavingthe way for Cassini," says Linda Spilker, Cassini project scientist at JPL, who started her career working on Voyager from 1977 to 1989. "On Cassini, we still compare our data to Voyager's and proudly build on Voyager's heritage." But the Voyager Mission left a few mysteries that Cassini has not yet solved. One of the most perplexing mysteries is Saturn's hexagpn. NASA scientists first spotted a hexagonal weather pattern when they stitched together Voyager images of Saturn's north pole. Cassini has obtained higher-resolution pictures of the hexagon – which tells scientists it's a remarkably stable wave in one of the jet streams that remains 30 years later – but scientists are still not sure what forces maintain the object. After the sunlight faded, darkness shrouded the north pole for 15 years. The hexagon was originally discovered in images taken by the Voyager spacecraft in the early 1980s.
How Long Has Titan's Chemical Factory Been in Business? Saturn’s giant moon Titan hides behind a thick, smoggy atmosphere that’s well known to scientists as one of the most complex chemical environments in the Solar System. It’s a productive “factory” cranking out hydrocarbons that rain down on Titan’s icy surface and cloak it in soot. With a brutally cold surface temperature of around minus 270 degrees Fahrenheit (minus 170 degrees Celsius), the hydrocarbons form lakes of liquid methane and ethane. Studying chemical processes on Titan could help astrobiologists understand the principles of prebiotic chemistry that operated on the early Earth at a time when life was first gaining a foothold on our planet. However, the most important raw ingredient in Titan’s chemical factory is methane gas. These papers used data collected by two instruments onboard NASA’s Cassini spacecraft in orbit around Saturn and one instrument on the European Space Agency’s Huygens probe that landed on Titan’s surface in January 2005.