Tag Archives: Saturn

Shorter days for Saturn

Saturn
Saturn

Using the change of radiation as Saturn's magnetic field rotates, the Voyager spacecraft measured almost 30 years ago that a day of Saturn lasts 10 hours, 39 minutes, and 24 seconds. However, the same measurements by the Cassini spacecraft suggests that it lasts 10 hours, 47 minutes, and 6 seconds, over seven minutes longer. Such a significant change in the bulk rotation rate of Saturn probably means that Saturn's magnetic field does not quite rotate in lockstep with the planet itself. Another method might be needed to measure the length of a Saturnian day.

Continue reading Shorter days for Saturn

The not so perfectly smooth rings of Saturn

I have always been impressed by how smooth the rings of Saturn look like. But the rings are actually made up of small chunks of ice, and sharp-eyed users at the Unmanned Spaceflight.com forum noticed that thousands of small boulders and moonlets were casting shadows on the ring, reminding us that the ring is not just one huge solid thing. It helps that the Sun is now lower on the horizon from the viewpoint of the rings, which means that longer shadows are cast.

Shadows cast on the rings of Saturn
Shadows cast on the rings of Saturn

Hail through Saturn's ring plane

The Cassini spacecraft just tweeted about what it sounded like when it arrived at Saturn and passed through the ring plane in 2004. While the spacecraft did not fly through the visible rings, there seems to be enough dust forming an invisible ring where it passed through to pelt the spacecraft with a lot of dust. These must have been truly microscopic dust, since if they were big enough to be visible enough to be seen by the naked eye, they would probably have destroyed the spacecraft at the speeds it was traveling.