In tomorrow morning’s eastern sky, two bright planets, Venus and Saturn will be at a very close conjunction, separated by less than half a degree.
Saturn’s rings, by the way, have recently been revealed to have more “3-D” structure than previously understood. Ironically, the structure of the rings was discovered this year, when they are almost invisible from Earth! Really–throughout this year, Saturn’s rings are pretty close to edge-on to the Sun, and for a couple of months around Saturn’s equinox, they are really really edge-on. This means, of course, that they are less visible from Earth this year than at any other time (except one) in the planet’s 30-year orbit around the Sun. (The exception, of course, is 15 years later, when Saturn is 180 degrees farther along in its orbit, and, once again, the rings will be edge-0n to the Sun, thus reflecting the least amount of light possible.) This now-you-see-’em-now-you-don’t nature of the rings confused the heck out of Galileo, who in 1610 was the first person on Earth to see these “strange appendages” of the planet. Imagine his surprise when he returned to observe the planet a few years later, when the rings were edge-on. Through the telescopes of the day, it looked as though they had completely disappeared!
When the rings are like this, it is possible, if you are not Earthbound, to take images of the rings from slightly above or below the plane, and study the shadows that Saturn’s moons cast across the rings. And that’s what the Cassini spacecraft did this summer, thereby exposing this hitherto unknown “verticality” to the rings. Go NASA!
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