That same evening, Saturn lies 5° east-northeast of Venus. The inner planet’s eastward motion relative to the background stars carries it 3° south of the ringed planet the evenings of October 29 and 30. Look for magnitude 0.5 Saturn to the upper right of Venus.
Saturn doesn’t look as spectacular through a telescope this month as it did during the spring and summer. Its lower altitude means that we view it through more of the distorting effects of our planet’s atmospheric turbulence, resulting in poor “seeing.” Still, the view is worth the effort. Saturn’s disk measures 16" across in mid-October while the rings span 35" and tilt 26° to our line of sight. The dark Cassini Division that separates the outer A ring from the brighter B ring should appear conspicuous in decent seeing.
You also should see several of Saturn’s satellites. The brightest, 8th-magnitude Titan, shows up easily through any scope. It orbits the planet in 16 days and slides due south of Saturn on October 2 and 18 and north of the planet on October 11 and 27. The ringed world’s three 10th-magnitude moons — Tethys, Dione, and Rhea — are a bit harder to see with the planet so low. Still, a 4-inch instrument with good optics should pick them up on most evenings.
As Venus and Saturn dip toward the horizon, shift your focus up to Mars. The Red Planet lies among the rich star fields of Sagittarius. In early October, the magnitude 0.1 world is a magnificent sight posed against a stunning backdrop. On the 1st, it lies in the same binocular field as the Lagoon Nebula (M8), which stands 2.5° to the northwest.
The planet moves 0.8° south of 7th-magnitude globular cluster M28 on October 5. Lambda (λ) Sagittarii, the 3rd-magnitude red giant star that marks the top of Sagittarius’ Teapot asterism, resides in the same low-power telescopic field. The next evening, Mars passes 0.2° south of this star.
The planet skims 4' south of the 9th-magnitude globular NGC 6638 on October 7. Mars rounds out its encounters with globulars on the 9th, when it appears 1.6° south of 5th-magnitude M22. You’ll want to view these vistas soon after the sky darkens while Sagittarius is still reasonably high.
The Red Planet stands out this month largely for the company it keeps. Its disk measures only 8" across and won’t show the surface features it did a few months ago. You’ll likely need an 8-inch or larger scope with fine optics and good seeing conditions to spot any appreciable details.