Saturn’s moon Iapetus is visible close to the ringed world today, along with several other of the planet’s brighter moons.
Iapetus is visible north of Saturn overnight on Aug. 9/10 as it heads for western elongation. Saturn’s other bright moons also cluster nearby; some will be easier to spot than others. Credit: Astronomy: Roen Kelly
- Saturn, at magnitude 0.7, is observable in the early morning hours (around 4 AM local daylight time) at approximately 45° altitude in the south, near the Circlet asterism in Pisces.
- Iapetus, Saturn’s two-toned moon, is visible at magnitude 11, located slightly northwest of Saturn during the early morning observation period.
- Several other Saturnian moons are also potentially visible using a telescope, including Titan (magnitude 8), Rhea (magnitude 10), Tethys (magnitude 10), and Dione (magnitude 10), with their relative positions specified.
- Enceladus (magnitude 12) may be observable with larger telescopes under clear skies, positioned west of Saturn’s rings.
Saturn’s two-toned moon Iapetus stands 1.5′ north of the ringed planet early this morning, shining around 11th magnitude. Spending much of its time far from Saturn, Iapetus rotates in lockstep with its orbit, so that its magnitude changes throughout its orbit as its brighter or darker hemisphere faces us. When it is north or south of Saturn, it is in the middle of this range. Coupled with its proximity to the planet, it’s easier to spot at such times. Give it a try in the early-morning hours — around 4 A.M. local daylight time, Saturn is roughly 45° high in the south, hanging to the lower left of the Circlet asterism in Pisces. At magnitude 0.7, the planet is the brightest point of light in this region of the sky.
Use a telescope to zoom in on the gas giant and enjoy the view of its rings as well as several of its larger, brighter moons. The largest and brightest of those satellites, 8th-magnitude Titan, lies west of the planet. Closer in on that side, you may also spot 10th-magnitude Rhea. Eleventh-magnitude Iapetus is slightly northwest of the planet early this morning. Tethys and Dione, both 10th magnitude, lie east of Saturn. There are several other moons as well, but they are fainter than 11th magnitude and thus more difficult to see. You could try for 12th-magnitude Enceladus just west of the rings if you have a larger scope and clear skies.
Sunrise: 6:07 A.M.
Sunset: 8:03 P.M.
Moonrise: 9:00 P.M.
Moonset: 7:25 A.M.
Moon Phase: Waning gibbous (98%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
For a look ahead at more upcoming sky events, check out our full Sky This Week column.
