The Sky Today on Saturday, October 3: Dione transits Saturn

The small saturnian moon Dione passes in front of the ringed planet, bringing its tiny shadow along for the journey. | Published: October 3, 2026 Late on the 3rd, Dione is transiting Saturn’s north polar region along with its shadow. Tethys and Rhea (not shown) lie to the planet’s west, while Titan (also outside this field of view) is far to the east. Credit: Stellarium/Oleg Pluton Looking for a sky event this week? Check out our full Sky This Week column. October 2: Venus stands still The small moon Dione transits Saturn starting just before midnight EDT. Tenth-magnitude Dione crosses the far northern region of the planet, beginning its journey just minutes after 11:40 P.M. EDT and taking about an hour and a half to complete the crossing. Its tiny shadow accompanies it, but said shadow will be all but impossible to pick up visually. Astrophotographers experienced with high-speed planetary video capture might catch it, though, so if that’s your forte, give it a try! The shadow is visible just north-northwest of Dione, very close to the moon itself. While Dione is transiting, look also for Tethys and Rhea, two moons of similar brightness that lie close to Saturn. Both are to the planet’s west, with Tethys closer to the planet than Rhea. Titan, some 1.5 magnitudes brighter, lies 3.3’ east of Saturn, on the planet’s other side. Sunrise: 6:58 A.M.Sunset: 6:39 P.M.Moonrise: — Moonset: 2:50 P.M.Moon Phase: Waning crescent (44%)*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location. Alison Klesman is senior editor of Astronomy magazine. She holds a Ph.D. in astronomy and has studied a variety of topics, from minor planets to supermassive black holes.