January 20, 2021: Mercury is low in the west-southwest after sunset. The bright moon is to the lower right of Mars, while the Red Planet passes planet Uranus.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 7:13 a.m. CST; Sunset, 4:51 p.m. CST. (Note that sunset is approaching 5 p.m. CST) Check local sources for sunrise and sunset times for your location.
During bright evening twilight, Mercury is over 7° in altitude above the west-southwest horizon. A binocular is needed to see the speedy planet hiding in the bright twilight.
The moon is near Mars this evening. One hour after sunset, the slightly gibbous moon is 7.3° to the lower right of Mars. The moon was at its First Quarter phase at 3:02 p.m. CST.
The Red Planet is dimming as our planet moves away after passing between Mars and the sun during October 2020. The increasing distance means the planet appears smaller through a telescope and dimmer to the unaided eye.
Mars passes 1.6° above dim planet Uranus this evening. To find it, first locate dim 19 Arietis (19 Ari on the chart). The star is 0.7° to the lower left of Mars. Use a binocular to locate the aquamarine “star” that is slightly larger than twice the Mars – 19 Ari distance below Mars. You’ll need at least 100x in a telescope’s eyepiece to see the spherical nature of the planet. The planet does not appear large even with that telescopic magnification, just appearing as an ultra-miniature world at its distance from Earth.
Read about Mars during January.
Detailed Note: One hour before sunrise, Regulus (α Leo, m = 1.3) is less than 30° up in the west. If you’re still looking for Venus, it is over 3° in altitude in the southeast at 30 minutes before sunrise. The moon is at its First Quarter phase at 3:02 p.m. CST. Jupiter sets at Civil Twilight. At this time, Mercury is over 7° in altitude in the west-southwestern sky. Nearly 63° in altitude in the south, the moon (7.8d, 51%) is 7.3° to the lower right of Mars. The Red Planet passes 1.6° above Uranus. The planet is 8.8° below Hamal and 0.7° to the lower left of 19 Ari.
Read more about the planets during January.
For a consolidated view of the daily activity of the planets and moon, subscribe to the Sky Calendar from Abrams Planetarium for $12 for a year. Each month’s sky events are displayed in calendar form. The opposite side of the page includes a star map. This is an easy reference to put on your refrigerator or bulletin board. No technology needed! Monthly calendars are mailed each quarter.
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.