During morning twilight brilliant Morning Star Venus shines from low in the east-southeast before sunrise as it steps eastward in front of the stars of Virgo. The gibbous moon lies in front of the stars of Cancer, between Leo and Gemini. In the evening sky. Jupiter continues to dance toward Saturn in a prelude to the Great Conjunction on December 21, 2020. In the east-southeast, Mars marches eastward among the dim stars of Pisces.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 7:03 a.m. CST; Sunset, 4:20 p.m. CST. Check local sources for sunrise and sunset times in your location. Add the time intervals in the notes to your local sunrise or sunset times.
Morning: An hour before sunrise, brilliant Venus is low in the east-southeastern sky, to the lower left of the star Zubenelgenubi, the brightest star in Libra. Use a binocular to spot dimmer Nu Librae (ν Lib on the chart) to the lower left of Venus. With a binocular watch Venus pass the dimmer star and move away from it during the next few mornings.
Farther west, the bright gibbous moon is nearly two-thirds of the way up in the sky in the west-southwest. It is among the dim stars of Cancer, between the star Regulus, in Leo, and the Gemini Twins – Pollux and Castor.
Morning detailed note: One hour before sunrise, brilliant Venus is nearly 12° in altitude above the east-southeast horizon and 2.3° to the lower left of Zubenelgenubi. Use a binocular to see dim Nu Librae (ν Lib, m = 5.2) 1.7° to the lower left of Venus. Watch Venus pass and move away from ν Lib during the next few mornings. Through a telescope, Venus is 11.5” across and 90% illuminated, a morning gibbous. Meanwhile, in the west, the bright gibbous moon (20.3d, 76%) is nearly two-thirds of the way up in the sky in the west-southwest. It is between Gemini and Leo, in the dim constellation Cancer. It is nearly midway from Regulus (α Leo, m = 1.3) and Pollux.
Evening: In the evening sky, Jupiter is low in the southwest as the sky darkens, 1.7° to the lower right of dimmer Saturn. Both planets resemble overly bright stars – the brightest in this region of the sky. Jupiter continues to close the gap to Saturn as the Great Conjunction approaches. Use a binocular to watch Jupiter and Saturn move relative to the dim star 56 Sagittarii (56 Sgr on the chart). Saturn is slowly approaching an even dimmer star Sigma Capricorni (σ Cap.)
Read about Mars during December.
Farther east, Mars is nearly halfway up in the east-southeastern sky. It is a bright rusty “star,” dimmer than Jupiter. With a binocular spot the Red Planet in a small triangle of stars, Epsilon Piscium (ε Psc on the chart), Zeta Piscium (ζ Psc), and 80 Piscium (80 Psc). It is to the right of a line from ε Psc to ζ Psc.
Evening detailed note: One hour after sunset, Jupiter is over 18° up in the southwest, 1.7° to the lower right of Saturn. Great Conjunction Countdown: 16 days. Among the stars, Jupiter and Saturn are near 56 Sagittarii (56 Sgr). Jupiter is 2.7° to the left of the star, while Saturn is 4.0° to the upper left of 56 Sgr. Additionally, Saturn is 4.1° to the lower right of Sigma Capricorni (σ Cap). Mars – over 40° up in the east-southeast – is 81.0° of ecliptic longitude east of Jupiter, over 40° up in the east-southeast. The gap between the two planets grows slowly as Mars picks up speed as it marches eastward in Pisces. With a binocular spot the Red Planet inside a triangle made by Epsilon Piscium (ε Psc), Zeta Piscium (ζ Psc), and 80 Piscium (80 Psc). The planet is 1.2° to the lower left of ε Psc and 1.5° to the upper right of ζ Psc. Mars is to the right of a line from ε Psc to ζ Psc. Make nightly observations of the morning and evening planets to see them move compared to their starfields. Through a telescope, Mars is 13.7” across.
Here is more about the planets during December 2020.
April 25, 2021: Mercury passes Evening Star Venus this evening after sunset. Look low in the western sky about 20 minutes after sunset. Mars is marching eastward in Gemini, near the star cluster Messier 35. The bright moon is near Spica.
April 25, 2021: Morning planets Jupiter and Saturn are in the southeast before sunrise. Jupiter is in front of the stars of Aquarius, while Saturn’s starry background is Capricornus.
April 24, 2021: Brilliant Evening Star Venus and bright Mercury are entering the evening sky. They are low in the west-northwest during evening twilight. The bright moon is in the southeast in Virgo. Mars moves into Gemini as it approaches the star cluster Messier 35.
April 24, 2021: The bright gibbous moon is near a star in Virgo during the early morning. From parts of the Western Hemisphere, the moon covers the star. Before sunrise, bright morning planets, Jupiter and Saturn are in the southeast before sunrise.
April 23, 2021: Evening Star Venus and Mercury are entering the evening sky. They are found very low in the west-northwest after sunset. The bright moon is in the southeastern sky during the early evening. Mars is moving toward the star cluster Messier 35.