Ask Astro is a favorite column in Astronomy Magazine. Readers submit questions, and the magazine finds astronomers with the answers. In the February issue, our own Emeritus Professor Richard Durisen and NASA Scientist Paul Estrada answered the question, “Do Saturn’s rings cast shadows?”
The rings do cast shadows, but Dick and Paul point out those shadows are nearly impossible to see from Earth. The shadows are hard to see because we’re basically right between the Sun and Saturn. Our view of the shadows is blocked by the bright rings themselves. Twice during Saturn’s roughly 30-year trip around the Sun, we see the rings edge-on – and their shadow on Saturn is extremely thin – thinner than an arc second. At those times, it’s possible, but difficult to see the rings’ shadow, because the Earth’s atmosphere blurs our view. The rings’ shadow can be seen with a combination of good atmospheric seeing and good telescope resolution.
Dick and Paul point to the spectacular images taken by NASA’s Cassini spacecraft in orbit around Saturn for good views of the rings’ shadows.
See Dick and Paul’s full answer at https://www.astronomy.com/science/do-saturns-rings-cast-shadows/.
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