September 18, 2022: The thick crescent moon and Mars are in the southeastern sky before sunrise. Daylight slips quickly as the equinox approaches.
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by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:34 a.m. CDT; Sunset, 6:55 p.m. CDT. Check local sources for sunrise and sunset times for your location.
Today, daylight is 12 hours, 21 minutes long. The equinox (September 22, 8:04 p.m. CDT) is nearing and daylight is shrinking quickly. For Chicago, there is no single day of 12 hours of daylight and darkness. The closest occurs on the 25th and 26th when the daytime length is a minute or so away from that “perfect” balance of 12 hours.
The overnight display of three bright planets and the moon continues. The best time to look is for night owls and very early risers, five hours before sunup. That’s around 1:30 a.m. in Chicago.
By an hour before sunrise, the thick-crescent moon, 45% illuminated, is high in the east-southeast. It is at the foot of Castor, one of the Gemini Twins. It is 17° to the left of Mars.
Mars is marching eastward in front of Taurus, heading toward the Bull’s horns, Elnath and Zeta Tauri. It passes between them before beginning its retrograde on October 30.
Through a binocular, the Red Planet is to the lower left of Tau Tauri (τ Tau on the chart) and to the upper right of Iota Tauri (ι Tau). On the 23rd, Mars passes 0.4° to the upper left of Iota. Look each clear morning to note the separation between Mars and the distant star.
Move the binocular slightly to place the moon near the middle of the field of view. The star cluster cataloged as Messier 35 (M35) is in the field of view with the lunar orb. The cluster is 2.7° to the lower right of the moon.
Messier 35 is a star cluster similar to the Pleiades and Hyades clusters in Taurus. It has over 100 stars and together the bunch spreads across the sky in a size that is about the same as the moon. Being nearly 3,000 light years away, the cluster is about 30 light years across. These two factors make the cluster seem to be about the same size in the sky as the moon.
In comparison, the famous Pleiades cluster, resembling a tiny dipper on the shoulder of Taurus, is only about 400 light years away. Its stars are intrinsically brighter than those in Messier 35.
The M35 cluster is far behind the plane of the solar system and makes a nice marker to note the passage of the planets. Mars passes by later next year after its retrograde and opposition.
On the 21st, the lunar crescent is in the same binocular field with the Beehive star cluster among the stars of Cancer.
At this hour, bright Jupiter is only about 20° up in the west-southwest. On the 26th, the Jovian Giant is at its opposition with the sun, meaning Earth is between the two wonders. While near opposition, the planet is retrograding in front of Pisces. This effect is an illusion from our faster-moving planet lapping the more distant Jupiter.
On October 1st, Venus and Jupiter are at opposition. Again, Earth is between the two. After this date, Jupiter sets before Venus rises.
This morning, Venus rises 47 minutes before sunrise. It is visible low in the east-northeast during brighter twilight, if you can locate a clear horizon.
After sundown, Saturn and bright Jupiter are in the eastern sky. Each evening, as Jupiter approaches its opposition, it is higher in the east after sunset. On opposition evening it rises at day’s end and appears to move across the sky during the night. Its appearance in the sky is “opposite the sun,” rise at sunset, south at midnight, set at sunup.
Saturn is low in the southeast, at one hour after sunset. It continues its retrograde in eastern Capricornus near Deneb Algedi and Nashira. To the unaided eye, the planet is noticeably west of the two stars.
Track the Ringed Wonder’s progress through a binocular as it closes in on Iota Capricorni (ι Cap).
Saturn leads the planet parade westward. Over a month after its opposition, Saturn rises before sunset and appears at this southeast position, while Jupiter is immediately above the horizon. A few hours later Mars rises, followed by the moon. By five hours before sunrise the overnight planetary display is similar to this morning, although the moon is farther eastward.
Don’t wait too late during the nighttime hours to view this spectacle. Saturn appears lower in the western sky during the predawn hours, setting over two hours before sunrise. It sets before Venus rises during brighter twilight.
- 2023, October 12: Bright Morning Planets Bookend Stellar SpectacularOctober 12, 2023: Before sunrise, brilliant Venus and Jupiter bracket the Milky Way’s bright Orion region.
- 2023, October 11: Morning Earthshine, LeoOctober 11, 2023: The morning’s thin lunar crescent displays earthshine as it appears near the constellation Leo.
- 2023, October 10: Morning Venus-Moon-Regulus Gathering, Venus-Saturn OppositionOctober 10, 2023: This morning Venus, the crescent moon, and Regulus gather in the eastern sky for a beautiful celestial display. Venus and Saturn are at opposition today.
- 2023, October 9: Venus-Regulus Conjunction, Morning Crescent MoonOctober 9, 2023: The Venus-Regulus conjunction occurs this morning. The morning crescent moon is above Venus during twilight.
- 2023, October 8: Celestial Barnyard, Convergence at RegulusOctober 8, 2023: The moon is visible with a celestial barnyard during morning twilight. Venus and the lunar crescent head for a celestial gathering in two mornings.