Sky Tour Podcast for September 2026
This month’s episode is sponsored by Celestron, manufacturer of high-quality telescopes and an industry leader in developing exciting optical products with revolutionary technologies.
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I’m Kelly Beatty of Sky & Telescope magazine, and tonight we’re going on a tour of the stars and planets that you’ll see overhead during September. First, we’ll check the calendar for this month’s equinox and Harvest Moon; then we’ll track down the bright planets, explore some lesser-known constellations, and bounce around the Summer Triangle. It’s a great introduction to the late-summer sky. So grab your curiosity, and come along on this month’s Sky Tour.
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Ask a stargazer about September’s astronomical significance, and the answer you’ll most likely get is: “the autumnal equinox.” It marks the celestial end of summer and the beginning of autumn in the Northern Hemisphere. This year, September’s equinox takes place on the 22nd at 8:05 p.m. Eastern Daylight Time. At that moment the Sun shines directly overhead when highest in the sky as seen from the equator. Days and nights are both 12 hours long — that’s where the word equinox comes from — and no matter where you live the Sun rises due east and sets due west.
There’s another celestial event associated with this equinox, and that’s the Harvest Moon on September 26th. Traditionally, according to records going back more than 300 years, it’s the name assigned to the Full Moon that falls closest to September’s equinox. The Harvest Moon gets its name from a geometric oddity. At this time of year the lunar orbit makes a shallow angle with respect to the eastern evening horizon. This causes the Moon to rise only about 30 minutes later on successive evenings, not the usual 50 minutes or so. So it never really gets dark between sunset and moonrise for several successive evenings, and that was a boon to farmers working late to try to harvest their crops at day’s end. 
Native Americans often called this the full Corn Moon, to note when those tall stalks could be harvested. Last quarter is on the 4th, new Moon falls on the evening of September 10th in the Americas, and first quarter on the 18th. So this timing means the Moon will be in the evening sky for the middle of the month and relegated to late-night and predawn appearances at the beginning and the end.
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The bright planets are scattered all over the morning and evening sky this month. Let’s start out with what you can see before dawn. Now, stop groaning. This time of year you can head out around 5 a.m. early in September and closer to 6 a.m. at month’s end, and it’ll still be dark enough to pick out lots of stars and planets. 
Most obvious is Jupiter, which rises roughly around 3 a.m. and is well up in the east as dawn approaches. Now swing your gaze all the way across the sky, so you’re looking west, and you’ll easily spot Saturn. It’s roughly just as high above the horizon as Jupiter but quite a bit fainter. Both of these planets are kind of by themselves, with no bright stars nearby, which makes it a snap to see them. And here’s a little secret: You don’t have to get up early to see Saturn. Nope, because it pops into view over the eastern horizon by about 9 p.m. early in September and by 7 p.m. at month’s end.
The third predawn planet is Mars, which is a little trickier to spot. Look for it above Jupiter by about three times the width of your clenched fist held at arm’s length. For most of September Mars is tangled up in the stars of Gemini, especially Castor and Pollux, which are about the same brightness. But the ruddy hue of Mars should give its identity away.
While you’re out this early, take a moment to admire the iconic constellation of Orion, high in the south, striding a bit farther westward week by week. By December, the mighty Hunter will be returning to our evening skies along with Sirius, to his lower left in Canis Major, and a host of other bright stars.
Meanwhile, Mercury is playing hide and seek with the Sun right now. And although technically it’ll be very low in the western sky just after sunset, honestly you’re very unlikely to see it. This will be the little planet’s poorest showing of the entire year.
That leaves Venus, which is wrapping up a nice run in the west as day turns to night. Venus is hand’s down the brightest planet, but it’s been diving toward the western horizon the past few weeks. So look for it while you can, low in the west about 30 minutes after sunset. If it’s clear on the 13th and 14th, Venus will be joined by a thin crescent Moon, making for a pretty scene in the deepening twilight. A closer look might show you the star Spica, much fainter than Venus and positioned a bit to its right. 
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Soon after the Sun goes down, as evening twilight is fading away, look almost directly above the sunset point, and you’ll see a bright star well up in the sky. That’s Arcturus, an ancient Greek name meaning “Guardian of the Bear” — in this case the constellation Ursa Major, the Big Bear, which is off to its right by about four fists. Arcturus is the 4th brightest star in the nighttime sky, both because it’s relatively close by (about 37 light-years away) and because it outshines the Sun by 170 times.
Now swing your view way to the left by about five fists, and a little farther down. That warm-hued star is the red supergiant star Antares, marking the heart of the constellation Scorpius. If you have a clear view toward south, look about three fists to the left of Antares for the Teapot-shaped stars of Sagittarius.
OK, I’d like to spend some time in the northern part of the sky this month, so hop back over to the Big Dipper in the northwest. Right now the Dipper really looks like its namesake, with the handle extending to the left and the four-star bowl on the right. Stargazers in England call this pattern the Plough, and you can see why. Or to you maybe it looks like a shopping cart! Remember, this distinctive pattern isn’t a constellation on its own, but it is the most obvious part of Ursa Major, the Big Bear, whose head and nose are to the Dipper’s right, and its legs are dangling below it and nearly touching the horizon at nightfall.
Take a close look at the middle star in the Dipper’s handle. Do you see something odd? Yep, that’s actually two stars very close together. Mizar is the obvious one, but just above it is a faint companion, called Alcor. These stars are both 83 light-years away, they’re moving through space together, and they’re roughly 1 light-year apart. After decades of debate, astronomers are finally agreed that they are truly orbiting one another. And actually there’s a total of six stars here, with Mizar comprising two double stars and Alcor a third.
The two stars at the right edge of the Dipper’s Bowl are often called the Pointer Stars, because if you follow an imaginary line upward from them, three fists away is Polaris, the North Star. This is at the end of the handle of the Little Dipper, which extends to the left, but some of its stars might be too faint to spot if you have a lot of light pollution. In that case, look about 1½ fists to the left of Polaris, and you have a good chance of seeing the two stars that mark the edge of the Little Dipper’s Bowl.
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Let’s go after some stars that are slam-dunk bright, even if you have a lot of light pollution. Lift your gaze way up to find a bright star that’s almost directly overhead. That’s Vega [VAY-guh]. It’s relatively close as stars go, just 25 light-years away. And, by the way, Vega plays a big role in the classic science-fiction movie Contact.
Since Vega is right overhead at nightfall, let’s use it to find three nearby compact, four-sided patterns. The first of these is to Vega’s immediate left, toward east. You’re looking for a parallelogram about as long as three outstretched fingers. These are the main stars of the constellation Lyra, the Lyre, and Vega is its alpha star.
Now look to Vega’s north by 1½ fists. This time look for a compact trapezoid, with two medium bright stars and two faint ones, also about three fingers across. This is the head of Draco, the Dragon, and its long line of stars snake from the head to form a curving line between the Big and Little Dippers. 
The third quartet is to the west of Vega. Its stars form a trapezoid that’s bigger than Draco’s, roughly the size of your clenched fist, but a little dimmer. This is known as the Keystone of the constellation Hercules, a great hero in Roman mythology, whose muscular torso and legs are represented by stars splaying out from the corners. Look westward beyond the Keystone toward Arcturus, a little more than one fist away, to spot a lovely semicircle of stars called Corona Borealis, the Northern Crown. This is the area that astronomers are hoping to see a nova erupt dramatically into view before the end of the year. For more details about that, check out SkyandTelecsope.org.
These four-star patterns might not be obvious if you have a lot of light pollution, but here’s one that’ll be unmistakable. Start at Vega and slide your gaze by about 2½ fists eastward, in the direction opposite Arcturus, to a prominent star. That’s Deneb. It’s roughly 100 times farther away than Vega — but it’s still quite the sparkler, isn’t it? That’s because Deneb is a real powerhouse of a star, pumping out up to 200,000 times more light than our Sun does.
Now look for a third bright star, Altair, about three fists to the south of Vega and four from Deneb. Week by week this trio of easy-to-spot stars, known collectively as the Summer Triangle, is gradually migrating westward in the sky. 
If you’re lucky enough to live in a really dark location, far from city lights, you’ll have no trouble seeing a delicately glowing river of light that we call the Milky Way vaulting high across the sky. That’s the combined light of countless stars in our galaxy’s midsection. As it turns out, some of its richest concentrations of stars are in the vicinity of Deneb. Can you see a faint glow up there? If you’re not sure, try again closer to midnight, when many lights have been shut off and Deneb itself is almost overhead. If you still can’t see the star cloud, you can blame light pollution, which sadly has robbed most of us of the chance to see the Milky Way at all.
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Thanks for letting me expand your celestial horizons for another month. If you want more tips for viewing the night sky, including a free, interactive star chart for any time or date, check out our website, SkyandTelescope.org.
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Sky Tour is a production of Sky & Telescope, a division of the American Astronomical Society, and is produced by me, Kelly Beatty.
Next month we’ll spend some time with Cassiopeia and find out why she’s so vain. Until then, I wish you Clear Skies.