Transient Events That Can Give Us a Good Enough Reason to Get Outside and Do a Little Observing
October 2026
All month: the evening sky cancels its sunset performance as Mercury and Venus become lost in the Sun’s glare, but Saturn and Neptune jump in with a mid-evening duet. Uranus makes a late evening appearance, sticking around past dawn for the morning crowd, with Mars and Jupiter joining the show in the wee hours. As the month begins, Mercury and Venus are challenging targets: at 6:54 pm CDT on Oct 1 (20 minutes after sunset), Mercury will be 3½° above the horizon, a 6 arcsecond gibbous orb glowing at mag -0.1, while Venus will be a gorgeous but elusive crescent barely 1½° up, a mag -4.7 arc 15% lit and 48 arcseconds tall – a rewarding view if you can manage it, but not a job for the faint of heart. Mercury reaches greatest eastern elongation on Oct 12 at 25° from the Sun, but less than 9° of that is vertical displacement due to the flat evening ecliptic. It remains a difficult target from the northern hemisphere all month, and reaches inferior conjunction on Nov 4. Venus is at inferior conjunction Oct 23. By Oct 31, it is again a challenge object: a vanishingly thin crescent, only 2% lit and 60 arcseconds tall, but blazing bright at mag -4.7 and 4° above the horizon at 7:01 am (20 minutes before sunrise). The earliest evening planet is now Neptune, a deep blue mag 7.8 disk 2½ arcseconds wide, rising at 6:22 pm as October begins, and two hours earlier as it ends. Saturn follows a half hour later throughout the month, as its 20 arcsecond disk dims from mag +0.3 to +0.5. The rings span 46 arcseconds and are tilted 7½° to our perspective, exposing the planet’s southern hemisphere to our view. Watch how the Seeliger Effect makes the rings appear brighter from a few days before to a few days after the planet reaches opposition on Oct 4: that’s because the chunks of ice that compose the rings block our view of their shadows in the direct sunlight, which also enhances backscatter lighting. Both Neptune and Saturn set in morning twilight by mid-month, and before sunrise by Oct 31, making the sunrise sky less interesting for early risers. Next up is Uranus, rising at 9:01 pm at the beginning of the month and 7:00 pm at its end, a pale blue-green mag 5.6 disk 4 arcseconds wide. It again spends the month parked between The Hyades and The Pleiades (M45), and will reach opposition on Nov 25. Mars follows at a leisurely distance, rising at 1:04 am when the month opens and 12:29 am when it ends. It brightens almost imperceptibly during October, from +1.1 to +0.9, as its disk grows slightly, from 5½ to 6½ arcseconds, still too small for good surface views. Mighty Jupiter rises last, at 2:37 am on Oct 1 and 1:03 am on Oct 31. In the interim, it brightens from mag -1.9 to -2.0, and grows from 33 to 36 arcseconds. Among the asteroids, 2 Pallas reaches opposition on Oct 6 at mag 8.2, followed by 4 Vesta at mag 6.5 on Oct 13. This month’s charts will show you where to find them.
Oct 4: during the wee hours tonight, a few minutes after 1 am CDT, a 30% lit crescent Moon will rise with The Beehive Cluster (M44) less than 2° below it, and ruddy mag +1.1 Mars the same distance above right. You’ll need binoculars or a telescope to see any of the cluster’s stars. The trio cross the sky together, the distances between them widening as the night goes on, with bright Jupiter following 14° behind the Moon. Watch them pass by before the stars disappear in morning twilight around 6 am.
Oct 5: stay up real late tonight (or get up real early tomorrow) to catch a rare occultation of Jupiter and its moons. It will take a full minute for mag -1.9 Jupiter to disappear or reappear along the edge of the 20% lit Moon, and a couple seconds for each of its moons to do so. Europa is first to slip behind the bright limb at 3:17 am CDT, followed by Io and Callisto 15 seconds apart at 3:19, Jupiter itself at 3:22, and Ganymede at 3:24. The moons may be impossible to spot in the bright lunar glare, even with a telescope, but they’ll be easily seen when they reappear, popping out from behind the dark limb: Europa at 4:10 am, Callisto at 4:12 followed by Io 45 seconds later, Jupiter at 4:15, and Ganymede at 4:17. Stick around a little longer to watch Ganymede’s shadow cross the planet starting at 4:37 am – the Great Red Spot will also be well-positioned then (it reaches meridian at 5:38 am). The entire show happens low in the eastern sky: 9° above the horizon when they disappear, 19° up when they come back, and 35° up when the GRS reaches meridian and Ganymede’s shadow is easy to spot. It’s the last Jupiter occultation visible from this part of the world until November 2037, so try not to miss it.
Oct 11: get up early for the show of the month as mag +1.1 Mars marches into the center of The Beehive Cluster (M44). With a telescope, you’ll be able to detect the planet’s motion against the well-populated starfield in as little as 10 minutes. Catch the view any time after Mars rises at 12:52 am CDT and before morning twilight washes out the starry background around 6:00 am. If you miss the tableau today, check it out tomorrow, when Mars will be just south of the cluster – not quite as dramatic, but still a pretty view.
Oct 12: new Moon arrived at 10:50 am CDT on Oct 10, so at 6:34 pm tonight (20 minutes after sunset) it will be 2.3 days old, 6% illuminated, 2½° above the horizon, and 23° left of the spot where the Sun went down. Mag -0.1 Mercury will be 2° higher and 3° to the right. But work fast, before the Moon sets at 6:52 pm.
Oct 14: turn your binoculars 8° above the SW horizon as soon as the sky darkens for a nice view of a narrow crescent Moon, 18% lit, with reddish Antares (Alpha [α] Scorpii) 1½° to its upper right and mag 2.8 star Tau (τ) Scorpii providing a blue-white counterpoint a quarter degree to the Moon’s left.
Oct 18: the Lunar X makes one of its rare nighttime appearances for a couple hours late tonight, beginning around 12:37 am CDT. You can find it along the terminator, about midway between the Moon’s equator and its south pole. Once you’ve spotted the X, scan northward to pick out its companion, the Lunar V.
Oct 21: the Orionids meteor shower peaks late tonight, but a gibbous Moon (80% illuminated) will be a problem until it sets around 3 am, although it’s 140° away from the radiant (which is between Orion’s club and the feet of Gemini). The shower remains at or above 50% of its maximum rate for a day on either side of peak, so it might be better to check it out the night of Oct 20, when the Moon will be slightly less glaring and 5° farther away. The Orionids are debris left by Comet Halley on its inbound path (Halley’s outbound debris forms a separate stream that gives us the Eta Aquarids in May). Expect around 5 meteors per hour – fast-movers, traveling at 66 km/second, with occasional bright fireballs.
Oct 27: find a good east horizon as the almost-full Moon (95% lit) rises in the midst of The Pleiades (M45) just after 6:30 pm CDT and occults several of the cluster’s members. They disappear behind the Moon’s bright limb before moonrise, but they’ll be visible in binoculars as they pop out from behind the narrow dark limb, beginning with 18 Tauri (mag 3.7) 6° above the ENE horizon at 7:13 pm; mag 3.9 Maia (20 Tauri) 9° up at 7:33 pm; and mag 2.9 Eta (η) Tauri, aka Alcyone, 13° up at 7:58 pm. The cluster pulls ahead of the Moon as the night goes on, with almost 5° separating them when morning twilight arrives around 6:30 am.
Rick Gering / October 2026