Saturn rises in the east soon before 9 P.M. local time on Aug. 1. It reaches opposition Aug. 14, so it is visible all night. The best time to view the planet is when it is highest in the southern sky, around 1 A.M. local time (local midnight using daylight saving time). It briefly brightens to magnitude 0.2 midmonth and is unmistakable within Capricornus the Sea Goat as the brightest object in this part of the sky.
You’ll find 3rd-magnitude Deneb Algedi (Delta [δ] Capricorni) near Saturn, 1.7° southeast of the planet as August opens. Saturn’s retrograde motion is easy to spot as the ringed planet wanders slowly westward at about 0.5° per week. August’s Full Moon, also opposite the Sun in the sky, lies within 5° of Saturn overnight on Aug. 11/12, shortly before the Perseid meteor shower peaks.
It’s the best time of the year to view Saturn’s rings, since the planet is closest to Earth at opposition (824 million miles), rendering the planet and its ring system at their largest apparent size to Earth dwellers. Saturn’s disk spans 19″ across the equator, but only 17″ from pole to pole — the planet’s somewhat flattened disk is now evident as the tilt of the rings reveals more of the southern polar regions.
The rings span nearly 43″ across and 10″ along the minor axis. Compare this year’s view to last summer’s, and you’ll notice the distinct change in ring tilt. By 2025, the rings will appear edge-on.
Titan, Saturn’s largest moon, is an easy target for small scopes. You’ll find it north of Saturn Aug. 5 and 21, and due south Aug. 13 and 29. On Aug. 19, a field star slightly dimmer than Titan’s magnitude 8.5 appears southwest of the planet; don’t confuse it for the moon, which lies southeast.
Closer to the rings, 10th-magnitude Tethys, Dione, and Rhea orbit with periods ranging from two to five days.
Two-toned Iapetus’ leading hemisphere is dark, causing the moon to appear faint at eastern elongations (12th magnitude) and brighter at western ones (10th magnitude). This month, Iapetus is brightest Aug. 7, when it reaches western elongation 9′ west of Saturn. It moves to superior conjunction early
Aug. 27 for U.S. observers.
Usually, Iapetus skims past the northern hemisphere of Saturn’s disk, but the current shallow tilt of its orbital plane causes an occultation instead. It’s a challenging event, given the brightness of Saturn and its rings, combined with Iapetus’ paltry 11th-magnitude glow. Digital imaging is likely to best capture the event. Iapetus lies just above the rings and begins to disappear around 12:25 A.M. EDT Aug. 27 (late on Aug. 26 in all other U.S. time zones).
Other moons also undergo eclipses and transits across the planet’s disk; these will increase over the next few years.
Neptune is an easy binocular object at magnitude 7.7. It starts the month in southwestern Pisces, 5° due south of Lambda (λ) Piscium, the Circlet’s southeasternmost star. You can also home in on Neptune by looking 13.5° southwest of Jupiter. The region is best viewed starting a couple of hours after midnight, when Neptune rises above 35° altitude in the southeastern sky.
Through binoculars on Aug. 1, you’ll find a star of similar brightness 0.4° to the planet’s east. Neptune’s motion carries it westward; on Aug. 31, the pair is 1° apart. A telescope will reveal the distant planet’s dim bluish disk, spanning a mere 2″. Neptune reaches opposition in September.
Sky This Month: August 2022
Source: Trending Update Article
0 Comments