I feel it is futile to apologize for lack of posting; anyone following this blog regularly must be used to it by now. The term ends in four weeks, and the theatrical production I’m involved with is in two weeks. I imagine I will be able to post more frequently when one or both of these have ended. So, please keep reading and if you have anything you want to see me write about particularly, please let me know!
In the meantime, here’s a great picture from the Cassini mission, in orbit around Saturn. Although Galileo was the first to observe the rings of Saturn (calling them “ears” because his telescope wasn’t good enough to tell their actual shape), Giovanni Cassini was the first to make a serious study of the rings’ patterns. In the 19th century, the great physicist James Clerk Maxwell, most famous for his discovery that light is electromagnetic in character, showed that the rings couldn’t be solid, but had to be made up of small pieces.
Today of course we’ve seen those rings up close, though the robotic Pioneer, Voyager, and now Cassini missions. We know that they are very wide — about 73,000 km wide — and very thin — only about 10 meters thick at their thickest point, and made almost entirely of ice. That by itself isn’t too surprising–rotation tends to flatten things out (think about a potter’s wheel)–but it’s amazing how beautifully-structured the rings are. In the picture above, you can see spiral ripples at the top of the image, caused by the passage of the tiny moon Pan in the top left corner.
This is actually a good time to see Saturn! In 2011, Saturn is quite bright, visible in the constellation Virgo. You won’t see the ripples in the rings, but with a good pair of binoculars you might catch a glimpse of Saturn’s “ears”, and a decent telescope will turn those “ears” into bright rings. And if that isn’t enough for you, the Cassini mission will keep you in pictures of Saturn and its glorious collection of moons for quite some time to come.