You might think it would be hard to hide something that’s 40,000 miles wide. But that’s exactly what Saturn will pull off this fall, when in a rare sort of celestial shell game its giant rings will vanish from sight. For years those myriad chunks of water ice encircling Saturn have been angling toward an increasingly edgewise slant. Now the action reaches a climax.
Saturn’s axial tilt is responsible for the pageant. The planet’s rings tip toward or away from us as the planet swings lazily in its 29-and- a-half-year path around the sun. Since that orbit is itself inclined 2.5 degrees to our own, we view it from slightly different angles over the years. Most of the time the tiny difference between the way the sun and Earth face Saturn has no effect on how we see Saturn illuminated. Only now, with the rings so close to edgewise, is ...
