Special Phenomena in which Saturn’s Ring Appears to be Invisible Occurs Just This Weekend

This image taken by NASA's Cassini spacecraft on Feb. 9, 2004, shows Saturn around 43 million miles (69 million kilometers) from the Cassini spacecraft. NASA/JPL/Space Science Institute

Starting on Sunday, March 23 at around 12:03 PM EDT, Saturn’s ironic rings will “disappear” for a couple of days as they align edge-on with Earth for the first time since 2009.

This cosmic illusion in which it seems that the ring around Saturn is invisible is caused by the specific tilts of both planets. Saturn’s axis is tilted at around 26.73 degrees from vertical as it orbits the sun. Similarly, the Earth orbits around the sun at a degree of 23.5 tilt, according to NASA. The rings are tilted so that they are either impossible to see or appear as a thin line crossing the planet's disk. This phenomenon happens every 13 to 15 years.

“They literally almost disappear,” said Sean Walker, an associate editor at Sky & Telescope, a monthly magazine about science and amateur astronomy. “Normally you see the rings around Saturn, but when you have an edge-on view, it looks like a hair-thin line of light just cutting across.”

Though, this time around Saturn will be too close to the sun, making it difficult for skywatchers to see it without its rings. But later this year on November 23, the rings will be nearly edge-on, allowing for a second opportunity for viewing.