by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:08 a.m. CDT; Sunset, 7:37 p.m. CDT. Check local sources for sunrise and sunset times. Times are calculated by the US Naval Observatory’s MICA computer program.
Today, daylight falls below thirteen hours, thirty minutes at Chicago’s latitude. It loses three to four minutes of light time each day during the next week.
Summaries of Current Sky Events
Here is today’s planet forecast:
Three bright planets – Venus, Jupiter, and Saturn – are visible before sunrise. Saturn is in the sky nearly all night as it nears opposition, rising nearly at sunset. After midnight this morning, the Ringed Wonder is less than halfway up in the sky, above the south-southeast horizon.
By an hour before sunrise, Saturn is less than 15° above the west-southwest horizon. With opposition imminent, the planet is retrograding in front of Aquarius, 8.2° to the lower right of Skat, the Aquarian’s leg, and 8.0° to the lower right of Lambda Aquarii (λ Aqr on the chart). The trio nearly forms an equilateral triangle.
Bright Jupiter rises less than three hours after Saturn and appears about 20° up in the east as the new calendar day opens. An hour before sunrise, the Jovian Giant is high in the south-southeast. At this hour it is the brightest star in the sky, even with Sirius twinkling wildly low in the east-southeast.
Jupiter continues to move eastward in front of Aries, 13.5° to the lower left of Hamal, the constellation’s brightest star, and less than 16° to the lower right of the Pleiades star cluster, part of Taurus.
Through a telescopic eyepiece at about 80x magnification, the star Sigma Arietis (σ Ari on the chart) is in the starfield, seemingly imitating Jupiter’s four bright moons. The star is west of Ganymede and Callisto at this hour.
At this hour at higher telescopic magnifications, the Great Red Spot, the planet’s long-lived atmospheric disturbance, is nearly at the center of the planet in the southern hemisphere. In nearly 30 minutes, the spot is at the center, but in brighter twilight for Chicago area sky watchers. Those farther westward see the planet in a dark sky.
Venus rises sixty-four minutes before sunrise, gaining seven minutes of rising time compared to sunrise for the next several days. At thirty minutes before daybreak, the planet is over 5° above the eastern horizon. Twilight is bright at this hour, but the planet is easily visible with an unobstructed view toward the east.
Mercury and Mars are east of the sun, hiding in bright evening twilight. Mercury is retrograding as it overtakes our planet on an inside orbital path, at a faster pace. Mars, much fainter than might be expected, sets about an hour after sunset. It is on a very slow slide toward its solar conjunction during November.
The bright moon, 57% illuminated, is less than 20° above the south-southwest horizon as night falls and 0.5° to the right of Antares, the bright red-orange star marking the Scorpion’s heart. With the bright moon’s proximity to the star, use a binocular to see the moon and the star in the same starfield.
From Chicago, beginning at 9:27 p.m. CDT, the dark edge of the moon covers Antares in an easily observed and slow-moving stellar eclipse, known as an occultation. The star reappears at the bright edge of the lunar orb at 10:32 p.m. This event is visible across most of the United States and southern Canada. In Austin, Texas, the event begins at 8:33 p.m. CDT and ends at 10:23 p.m. In Denver, the occultation begins at 8:01 p.m. MDT, ending at 9:11 p.m.
Just nights before opposition, Saturn rises less than 10 minutes after sunset. An hour later, find it nearly 10° above the east-southeast horizon. Find the planet farther westward during its all-night journey.
Jupiter rises in the east nearly three hours after Saturn rises.
- 2023, October 21: Three Bright Planets, First Quarter MoonOctober 21, 2023: Venus, Jupiter, and Saturn are easy to locate during nighttime hours. The First Quarter moon phase occurs this evening.
- 2023, October 20: Jupiter’s Double Shadows, Mercury at Superior ConjunctionOctober 20: After midnight, Jupiter’s moons’ shadows dance across the cloud tops. Mercury is at superior conjunction.
- 2023, October 19: Poured Moon, See Planet UranusOctober 19: Sagittarius seems to pour the moon into the sky this evening. Find Uranus with a binocular.
- 2023, October 18: Moon-Antares Conjunction, Bright PlanetsOctober 18, 2023: The moon is near Antares after sunset. Venus, Jupiter, and Saturn are in the sky during the nighttime hours.
- 2023, October 17: Scorpion MoonOctober 17, 2023: The crescent moon is with Scorpius during evening twilight. Venus and Jupiter gleam from the predawn sky.