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.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:44 a.m. CDT; Sunset, 6:39 p.m. CDT. Check local sources for sunrise and sunset times for your location.
An hour before sunrise, the gibbous moon, 65% illuminated, is high in the south. It is between the horns of Taurus, Elnath and Zeta Tauri. The moon is nearly midway from Aldebaran to Elnath.
A binocular can help identify the stars in this bright moonlight.
The evening pack of planets is visible after sundown. Brilliant Venus is about 8° up in the southwest. Find a clear view toward the horizon. The planet is 4.7° to the lower left of Zubenelgenubi and over 20° to the lower right of Antares. The planet passes the star next month. Observations each evening shows the speed that Venus moves eastward.
Venus sets nearly 100 minutes after sunset this evening.
Farther eastward, Jupiter and Saturn are in the southeast. Jupiter is bright, although not at the intensity of Venus. Saturn is to the upper right of Jupiter.
As night falls, the giant-planet duo is higher in the southern sky. As the calendar day ends, Saturn is in the southwest and Jupiter above the south-southwest horizon. Saturn sets about five hours before sunrise. Jupiter follows Saturn to the horizon nearly 90 minutes later.
Both planets continue to retrograde in Capricornus. While each rises into the eastern sky and sets at the western horizon, they are revolving around the sun. Their normal pattern, as they revolve around the sun, is to move eastward compared to the distant stars that make a backdrop to watch the planetary motions. Jupiter revolves around the sun in nearly 12 years, while Saturn revolves in nearly 30 years. They move slowly against the sidereal background, especially compared to Mercury and Venus. Mars moves quickly as well.
Nearly each year, Earth moves between the sun and each planet. As Earth catches up to the planet, passes between the planet and the sun, and begins to move away, the distant world seems to stop moving eastward and seems to go backwards or retrograde compared to those distant stars. This is only an illusion.
Saturn and Jupiter retrograde until later next month, when they resume their eastward direction compared to the distant stars.
Detailed Daily Note: One hour before sunrise, the moon (20.4d, 65%) is over 70° above the southern horizon, west of the meridian. It is between Aldebaran and Elnath (β Tau, m = 1.6). The lunar orb is 9.1° to the upper left of Aldebaran and 7.6° to the lower right of Elnath, not quite midway between the two stars. Venus is in the southwestern sky after sunset. Look for it 4.7° to the left of Zubenelgenubi and 1.7° to the lower right of ι Lib. It is 20.7° to the lower right of Antares. Jupiter and Saturn are in the southeastern sky when Venus is in the southwest. The brilliant planet sets 99 minutes after sunset. Two hours after sundown, Saturn is about 29° up in the south, east of the meridian. In the starfield, it is 1.4° to the lower right of υ Cap. Bright Jupiter is 15.9° to the east of the Ringed Wonder. Both continue to retrograde. Jupiter, nearly 30° up in the south-southeast, is 3.1° to the lower right of μ Cap, 1.6° to the upper right of Deneb Algedi, and 1.6° to the upper left of Nashira. As the calendar day closes, the moon (21.2d, 58%) is over 10° above the east-northeast horizon.
Articles and Summaries
October 7, 2021: The lunar crescent returns to the evening sky for a short visit in the western sky after sunset. The bright planet pack – Venus, Jupiter, and Saturn – are visible during the early evening.
Mars is at its solar conjunction on October 7, 2021. It begins a slow return into the morning sky. By year’s end it appears low in the southeastern sky with the moon.
October 6, 2021: The moon is at its New moon phase today. This evening look for the three bright planets after sunset.
October 5, 2021: Before sunrise, a very thin moon is visible in the eastern sky. The evening planet pack – Evening Star Venus, Jupiter, and Saturn – are visible at the same time after sundown.
October 29, 2021: Today is the date for equal daylight and equal darkness for about 42° north latitude. This is not to be confused with the autumnal equinox.