Satellite News

Spokes in Saturn’s rings. Image credit: NASA/JPL/SSIClick to enlarge
Nope, that’s not an error in the photograph. The ghostly white stripe in Saturn’s rings was captured by Cassini on July 23, 2006. This is the first time that Cassini has seen spokes in Saturn’s rings in nearly a year, and the first time from the sunlit side of the rings. Some scientists think the spokes might be caused by meteoroid impacts onto the rings. Others suggest they’re created by an instability in Saturn’s magnetic field.

Titan. Image credit: NASA/JPL/SSIClick to enlarge
New research from NASA, published in the journal Nature suggests that it’s always raining on Titan. Not thunderstorms, but a low level liquid methane drizzle that never stops. When Huygens landed onto the surface of Titan, it came down with a splat, presumably into mud. Scientists estimate that the amount of rain amounts to about 5 cm (2 inches) a year of accumulation – the same amount that falls in Death Valley on Earth. But this rain falls steadily, keeping the ground relatively damp.

Artist impression of Huygens. Image credit: ESAClick to enlarge
When ESA’s Huygens probe landed on the surface of Saturn’s moon Titan last year, it continued to transmit data for 71 minutes. The signal relayed through Cassini had a strange fluctuation in power as the angle between the lander and spacecraft changed. Researchers were able to reproduce this power oscillation when they realized that the signal was bouncing off of pebbles on Titan’s surface. They were able calculate that the surface around Huygens is mostly flat, but littered with 5-10 cm (2-4 inch) rocks.

Xanadu region on Titan. Image credit: NASA/JPL/SSIClick to enlarge
New radar images of Titan show surprisingly familiar terrain on Saturn’s largest moon. The radar images show a strip 4,500 km (2,796 miles) long, straight through the Xanadu region. Some images show hills, valleys and dark sand dunes cut by river networks – the similarity to Earth is striking. Of course, Titan is so cold it can’t be water; these rivers are probably formed by liquid methane or ethane. Cassini will return to Titan on Saturday, July 22 and capture images of the northern latitudes.