Saturn’s iconic rings will seemingly “disappear” from view this weekend as they align edge-on with Earth for the first time since 2009.
Every 13 to 15 years, the planet’s rings align perfectly with our line of sight, making them appear nearly invisible to viewers on Earth. This fleeting phenomenon, known as the “ring plane crossing,” will occur Sunday (March 23) at 12:04 p.m. EDT (1604 GMT), when Earth passes through Saturn’s ring plane, according to In-the-Sky.org.
Unfortunately, this ring plane crossing will be out of reach for most skywatchers to see. For those in mid-northern latitudes, Saturn is close to the pre-dawn sun and well below the slanted morning ecliptic for observers at mid-northern latitudes. Skywatchers in mid-southern latitudes will have the best chance to see Saturn without rings, but will have to compete with morning twilight over the eastern horizon.
The ringed planet completes one orbit around the sun every 29.4 Earth years. During this cycle, the visibility of Saturn’s rings when viewed from Earth changes because the planet rotates on an axis tilted at 27 degrees. Sometimes the rings are tilted so that we have a good view of them, and sometimes we view them edge-on, so that they are either impossible to see or appear as a thin line crossing the planet’s disk.
Saturn’s rings are primarily made of water ice, along with small particles of rocks and dust. They are believed to be remnants of comets, asteroids or shattered moons that were torn apart by the planet’s powerful gravity.
While Saturn’s rings stretch 170,000 miles across (273,600 kilometers), they are only about 30 feet (10 meters) thick, making them appear thin and wispy when viewed from any angle. However, when aligned edge-on with Earth, they reflect very little light and are nearly impossible to see.
Our view of Saturn shifts during the planet’s orbit around the sun. When Saturn is tilted toward us, we see the upper side of its rings. Whereas when the planet is tilted away from us we see the lower side of its rings. As Earth transitions between these perspectives, our planet passes through Saturn’s ring plane. As a result, we experience a ringless view of Saturn because we are in line with the edge of its rings.
The planet’s rings have been gradually tilting toward an edge-on alignment for the past seven years. Thankfully, however, this edge-on view is merely a temporary effect. Saturn’s rings will slowly begin to tilt back toward Earth and will appear as a thin line within a few hours. Over the next several months, they will gradually become more and more visible. In 2032, they will be at their best again during their period of maximum tilt as seen from Earth.
Even though the planet’s iconic rings won’t be visible for a while, viewers can still look for the bright planet as it rises low on the eastern horizon just before sunrise. The best time to see Saturn this year will be during opposition — when Earth is between the planet and the sun — on September 21, 2025. During opposition, Saturn will be at its brightest in Earth’s sky.
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