Saturn jumps into the spotlight for sky-watchers in September when it reaches opposition on the 21st. This means that from our earthly viewpoint we are right between the ringed planet and the sun.
Saturn rises in the eastern evening sky (opposite) as the sun sets along the western horizon. That also means that Saturn is at its brightest and closest to us for 2025.
Note, however, that Saturn is still 794 million miles away from us.
Telescope views will reveal Saturn’s beautiful rings, though at this time their tilt is only about 2% to our line of sight. So they will appear nearly edge-on.
Telescopes also will reveal several of Saturn’s many moons. The largest, Titan, will be making several transits of the planet. It will cast a shadow of itself across the face of Saturn, which telescopes will reveal on the nights of Sept. 3-4 and Sept. 19-20.
Recalling that Neptune has been visible to us over the last two months because it is in the same direct line of sight to us as Saturn, we will still use Saturn as the guide to spotting Neptune using binoculars this month.
Saturn’s motion has changed how close together the two planets appear to us because Neptune’s motion at its huge distance away does not show up as much.
To find Neptune this month, center Saturn in your view through binoculars, move above about a half of a field of view and Neptune should be near the center of your view as a bluish-green dot of light.
Jupiter is up in the eastern sky by 3 a.m. in September, outshining all the stars of Gemini around it. Look 90 minutes to two hours before sunrise for good views of the giant planet.
Jupiter’s four biggest moons, the Galilean moons (Galileo was first to see them in 1615), will be easily seen around Jupiter with binoculars, moving and changing positions nightly as they orbit the planet.
The autumnal equinox occurs at 2:19 a.m. Eastern Daylight Time on Sept. 23, marking the official start of fall. Day length, hours of darkness and light, are nearly equal then.
But the so-called Summer Triangle asterism rides almost directly overhead all month, consisting of three first-magnitude stars. Vega in Lyra the harp, Deneb at the tail of the Summer Triangle asterism and Altair marking the eye of Aquila the eagle stand out as a large and distinct triangle that will continue to be visible well into the fall as we slide past them in our orbit around the sun.
Venus is still very bright in the eastern morning sky before dawn though its orbit is making it appear to sink lower to the horizon all month.
On Sept. 1, Venus will be near the Beehive Star Cluster (M44) and on Sept. 19 it will be just above Regulus, brightest star in the constellation Leo the lion.
On Sept. 8, look for the nearly full moon just above Saturn in the eastern sky (full moon is actually on Sept. 7), and on Sept. 16 the waning crescent moon will be very close to Jupiter in the eastern sky before sunrise.