August 3, 2021: Four planets appear in the evening sky. Brilliant Evening Star Venus and dim Mars are in the west after sunset. A little later during the evening, Saturn and Jupiter are easily visible in the southeast.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:47 a.m. CDT; Sunset, 8:07 p.m. CDT. Check local sources for sunrise and sunset times for your location.
Four bright planets are visible after sunset and during the early evening hours.
Brilliant Evening Star Venus shines through the colorful hues of evening twilight. Look for it low in the west about 45 minutes after sunset. It continues to slowly climb into the western sky. It seems to have maintained this altitude in the sky for several weeks at this time interval after sunset.
Venus sets about 90 minutes after sunset every evening until mid-September. By-mid October its sets two hours after sunset.
Venus moves rapidly eastward compared to the starry background. It moves about 1.8° each evening. During the month, it moves toward the star Spica, the brightest in the constellation Virgo. The star is low in the southwest, outside the frame of the image above, nearly 39° to the upper left of Venus this evening.
Dim Mars is over 12° to the lower right of Venus. The Red Planet is about 5° above the horizon at this hour. It is a challenge to see from its low altitude in the sky and the planet is at its dimmest. Use a binocular to attempt to locate it.
In about two weeks, Mercury enters the sky and passes very close to Mars. This is a challenging observation at only 25 minutes after sunset on August 18. On this evening and for a few evenings around that day, the five bright planets – Mercury, Venus, Mars, Jupiter, and Saturn – are in the sky at the same time.
Yesterday, Saturn was at opposition. Earth was between the sun and the planet. Jupiter is at opposition on August 19.
Look for Saturn and Jupiter at about 90 minutes after sunset, when both planets are clearing the horizon’s visual obstructions.
Jupiter is the brighter of the two bright giant planets. At this hour, Jupiter is over 7° up in the east-southeast. Saturn is to Jupiter’s upper right, about 14° above the southeast horizon. The planets rise higher during the evening and are higher in the south near midnight. They are in the southwest before sunrise tomorrow morning.
If you are awake early tomorrow, look for the crescent moon in the eastern sky.
Detailed Daily Note: One hour before sunrise, Saturn is nearly 10° up in the southwest. Retrograding in Capricornus, the Ringed Wonder is 4.0° to the lower right of θ Cap. Bright Jupiter, nearly 25° up in the southwest, is 19.2° to the upper left of Saturn. The Jovian Giant, retrograding in Aquarius, is 0.9° to the upper right of ι Aqr. Farther eastward, the crescent moon (24.4d, 24%) is over 36° up in the east. The crescent is 5.9° to the upper left of Aldebaran. Sirius (α CMa, m = −1.5) rises at sunup. In the evening, 45 minutes after sunset, Venus is over 8° up in the west. Spica, about 20° up in the southwest, is 38.6° to the upper left of Venus. Watch Venus cut the gap to Spica. Farther east, Saturn is over 8° up in the east-southeast. At the end of evening twilight, Saturn is nearly 18° up in the southeast, while Jupiter is over 10° above the east-southeast horizon.
Articles and Summaries
September 30, 2021: An hour before sunrise, the crescent moon is near the Gemini Twins.
September 29, 2021: The thick crescent moon is in the southeast before sunrise, approaching the middle of Gemini. The evening planet pack is visible after sunset.
September 28, 2021: This morning the moon, as it approaches its Last Quarter phase, is high in the south at the Gemini – Taurus border. The evening planet pack – Venus, Jupiter, and Saturn – brightly shine after sunset.
September 27, 2021: Before sunrise this morning, the bright moon seems caught between the horns of Taurus, Elnath and Zeta Tauri. The planet pack, Venus, Jupiter, and Saturn, are visible after sundown.
September 26, 2021: This morning a bright moon is between the Pleaides and Hyades star clusters.