by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:13 a.m. CDT; Sunset, 7:29 p.m. CDT. Check local sources for sunrise and sunset times. Times are calculated by the US Naval Observatory’s MICA computer program.
The five-planet morning parade continues with Venus, Jupiter, and Saturn easily visible. Uranus is easy to locate through a binocular between Jupiter and the Pleiades star cluster. The challenging view, even through a binocular, is locating Neptune in a dim Pisces starfield, over 20° to the upper left of Saturn. For sky watchers interested in seeing the two more distant planets, see the directions in the August 27th article.
Summaries of Current Sky Events
Here is today’s planet forecast:
Step outside about an hour before sunrise. The easiest planet to locate is bright Jupiter, high in the southern sky. It is slowly moving eastward in front of Aries, 13.5° to the lower left of Hamal, the constellation’s brightest star, and nearly 16° to the lower right of the Pleiades star cluster.
The planet is slowing to begin retrograding early next month. During this illusion, Jupiter appears to move westward compared to the starry background. In reality, our world is overtaking the Jovian Giant, so the line of sight, that normally moves eastward against the starry background, begins to shift westward.
Jupiter makes its first appearance above the eastern horizon about three hours after sunset. By midnight, it is well-up in the east. At 4:55 a.m. CDT, the Great Red Spot is visible through a telescope at the center of the planet in the southern hemisphere.
Through a telescopic eyepiece providing 80x magnification, Jupiter’s globe and four largest satellites are visible. Look carefully at the planet to see parallel cloud bands that are whipped that way by Jupiter’s rapid rotation. The plane of the satellites is in Jupiter’s equatorial plane and from our view they line up on either side of the planet. Resembling stars this morning Io and Ganymede are east of Jupiter, while Europa and Callisto are to the west. Offset Jupiter from the center of the telescopic field of view toward the east. The distant star Sigma Arietis (σ Ari on the chart) is lined up with the moons, but it is beyond the farthest that Callisto appears from Jupiter. A few days ago, it appeared as if it were a new satellite close to Jupiter. The star serves as a distant reference point to watch the eastward-moving planet plod in that direction.
While Jupiter is high in the south, brilliant Venus makes a grand entrance into the morning sky. It is low in the east at one hour before sunrise, outshining all other celestial objects in this predawn sky. The Morning Star rises nearly one hundred minutes before the sun, gaining six to seven minutes of rising time each morning. The planet appears higher in the sky each morning as it gains rising time.
Look for Sirius, over 10° up in the southeast and over 40° to the upper right of Venus. Procyon is the star that is higher in the east, above an imaginary line from Sirius to Venus.
Venus and Sirius appear at the same altitude – height above the horizon – beginning about September 10. While Venus does not pass closely to Sirius, the brightest planet and brightest star appear in the eastern sky before sunrise.
Saturn, over 157° west of Venus, is less than 10° above the west-southwest horizon at this hour. It is retrograding in front of Aquarius, 8.4° to the lower right of Skat, meaning “the leg,” and 8.3° to the lower right of Lambda Aquarii (λ Aqr on the chart). Together the trio nearly makes an equilateral triangle.
Each morning Saturn is closer to the horizon at this time interval before sunrise. In several days it is no longer visible at this time.
Mercury and Mars are east of the sun and technically evening planets. The innermost planet sets less than ten minutes after the sun. It is overtaking Earth, moving between our world and the sun next month. It then appears in the morning sky.
Mars is much dimmer than might be expected. It sets about an hour after sundown.
The bright moon, 98% illuminated, is approaching its second Full moon phase this month, commonly known as a “Blue” moon. An hour after sunset, it is over 10° up in the southeast and nearly 12° to the right of Saturn.
- 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.