Astronomy for the Common Folk

Full Story and expanded caption: As Saturn's rings orbit the planet, a section is typically in the planet's shadow, experiencing a brief night lasting from 6 to 14 hours. However, once approximately every 15 years, night falls over the entire visible ring system for about four days. This happens during Saturn's equinox, when the sun is directly over Saturn's equator. At this time, the rings, which also orbit directly over the planet's equator, appear edge-on to the sun. During equinox, light from the sun hits the ring particles at very low angles, accenting their topography and giving us a three-dimensional view of the rings. Seen from our planet, the view of Saturn's rings during equinox is extremely foreshortened and limited. But in orbit around Saturn, Cassini had no such problems. From 20 degrees above the ring plane, Cassini's wide angle camera shot 75 exposures in succession for this mosaic showing Saturn, its rings and a few of its moons Aug. 12, 2009, beginning about 1.25 days after exact Saturn equinox, when the sun's disk was exactly overhead at the planet's equator. Credit: NASA/JPL/Space Science Institute

I love this comic about astronomy for the common folk. It reminds me of discussions I’ve had with our kids although I try to sound smarter with them.