2021, January 20: Mercury, Bright Moon, Mars Conjunction

2021, January 20: Mercury is low in the west-southwest during bright evening twilight.

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.

2021, January 20: The bright moon is 7.3° to the lower right of Mars. The Red Planet passes 1.6° above the planet Uranus.

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.

2021, July 6: Venus, Mars Final Approach

July 6, 2021:  In less than a week, brilliant Venus passes Mars in the west-northwestern sky after sunset.  This evening the two planets are 3.8° apart.  Venus is over 18° to the lower right of the star Regulus.

2021, July 1- 7, Morning Moon

July 1 – July 7, 2021, the waning crescent appears in the eastern sky.  Early in the viewing period, the moon is among the dim stars of Pisces.  As the week progresses, the moon wanes and moves farther eastward, appearing near Taurus.

2021, July 5: Earth at Aphelion

July 5, 2021:  Our planet Earth reaches its farthest point in its yearly trek around the sun.  Our seasons are not related to Earth’s distance from the sun.  Coincidentally, the moon is at its farthest point from Earth today.

2021, July 4: Venus Aims at Mars

July 4, 2021: The Venus – Mars conjunction is eight days away.  This evening Venus moves to within 5° of the Red Planet.

Categories: Astronomy, Sky Watching

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