Saturn's Rings Vanish Today

Saturn's rings will disappear from sight for three months starting today, Space.com reports. The rings, 170,000 miles long but only 30 feet thick, are visible because they reflect sunlight. But they vanish once every 15 years as equinoxes occur in its 30-year orbit and the rings are directly in line with the sun. This equinox marks the arrival of spring to Saturn's northern hemisphere.

"The light reflecting off this extremely narrow band is so small that for all intents and purposes the rings simply vanish," a NASA scientist explained. "Whenever equinox occurs on Saturn, sunlight will hit Saturn's thin rings, the ring plane, edge-on." (More Saturn stories.)