If you want to understand what causes the gaps in Saturn’s rings, just look at a picture taken by Cassini on October 27, 2006. The bright object in the middle of Saturn’s Encke gap is one of its moons: Pan. The tiny moon is only 26 km across, but its minor gravity can clear out the ring particles.
https://photojournal.jpl.nasa.gov/catalog/PIA08317
Kategorie: Saturn
Saturn’s spokes may be made by lightning
The mysterious spokes in Saturn’s rings may be created by massive thunderstorms in the planet’s atmosphere. If the theory is right, these faint features are the signature of awesome events: lightning strokes ten thousand times more energetic than those on Earth, releasing beams of electrons that surge up from Saturn’s surface to whack into the rings and blast out jets of electrically charged dust. The idea, proposed by Geraint Jones of the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany, and his colleagues remains speculative. No one has ever seen storm-induced electron beams on Saturn. But the researchers say that the theory would explain some puzzling features of the spokes, and that it fits with what is known about the effects of thunderstorms on Earth. The spokes of Saturn’s rings were first discovered by the Voyager I and II spacecraft when they passed close to the gas giant planet in 1980 and 1981.
Source : Jones G. H., et al. Geophys. Res. Lett., 33 . L21202 (2006)
Janus Poses Above Saturn
A new incredible photograph shows Saturn’s potato-shaped moon Janus posing above the planet’s cloudy atmosphere. Janus is only 181 kilometers across, and it shows the scars of many impacts with other objects. Like Saturn’s other smaller moons, Janus could be covered with a layer of fine, dust-sized icy material. The Cassini spacecraft took the photo on September 25, 2006, when it was only 145.000 kilometers from Janus.
https://photojournal.jpl.nasa.gov/catalog/PIA08296
Flooded rivers seen in new Titan images
Flooded rivers and more lakes have been spied on Saturn’s moon Titan in new images by the Cassini spacecraft. The features are all likely filled with liquid methane or ethane, providing insight into a methane cycle analogous to the hydrological cycle on Earth. Cassini has revealed dozens of dark areas by peering through the hazy atmosphere with its radar instrument. Previous flybys of the giant moon suggested these were lakes. The lakes seen by radar are clustered around the north polar region. They may be seasonal, accumulating at each pole from winter rains and drying up during the summer. Spring is now approaching for Titan’s northern hemisphere and some of the lakes there show indeed signs of evaporation. A lake with many lobes has been seen in the latest flyby of the moon, on October 9, 2006, suggesting it was created when a system of interconnecting rivers overflowed their banks to fill in the surrounding topography.
Lakes and More Lakes
Cassini at the DPS conference
The DPS conference in Pasadena is now in full swing. News and press releases are slowly trickling out of that conference, from New Scientist which reported on an Enceladus theory relating cosmic rays and Enceladus‘ jets to public releases at NASA’s Planetary Photojournal.
Here are some Cassini news from this conference:
PIA08329: In Saturn’s Shadow