2023, February 8: Gibbous Moon, Mars Marches Eastward


February 8, 2023: The gibbous moon is visible before daybreak and again later in the evening.  With brilliant Venus and Jupiter in the west-southwest, Mars marches eastward against Taurus in the southeastern sky.

Photo Caption – 2019, January 19: Venus- Jupiter, 3.7 degrees apart


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:56 a.m. CST; Sunset, 5:15 p.m. CST.  Check local sources for sunrise and sunset times for your location.  Times are calculated from the U.S. Naval Observatory’s MICA computer program.

Jupiter’s Great Red Spot’s transit times, when it is in the center of the planet in the southern hemisphere: 2:02 UT, 11:57 UT, 21:53 UT. Convert the time to your time zone. In the US, subtract five hours for EST, six hours for CST, and so on.  Use a telescope to see the spot.  Times are from Sky & Telescope magazine.

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, February 8: Before daybreak, the gibbous moon is in the western sky, below Denebola.

The waning gibbous moon, 93% illuminated, is about 30° up in the west-southwest about an hour before sunrise.  It is nearly 10° below Denebola – the Lion’s tail – and almost 20° to the upper left of Regulus.

The morning sky is without a bright planet.  Mercury rises 68 minutes before sunup and it is lost in the bright twilight in the southeast.

The planet continues to retreat into the sun’s glare for superior conjunction on the far arc of its solar orbit, moving toward its best evening appearance of the year.

Evening Sky

Chart Caption – 2023, February 8: After sundown, Venus and Jupiter are in the west-southwestern sky.

After sundown, a slow planetary dance is occurring in the west-southwest with brilliant Venus and Jupiter.  At forty-five minutes after sunset, the Evening Star is nearly 15° above the west-southwest horizon and 21.6° to the lower right of Jupiter.

Venus moves faster eastward than Jupiter and overtakes it on March 1st during a close conjunction.

Conjunctions of this pair occur every few years.  The next observable pairing occurs before sunrise on August 12, 2025.  A conjunction occurs May 23, 2024, but the two planets are too close to the sun for easy observation.

Beginning February 20th, Venus moves to within 10° of Jupiter.  The two brightest starlike bodies are in close proximity.  By March 12, the gap is larger than 10° when Venus is east of Jupiter.  For several days, the two planets are easy to see and track from night to night.

Chart Caption – 2023, February 8: During evening twilight, Mars is high in the southeast, to the upper left of Aldebaran.

Farther eastward, Mars, high in the southeast, is marching eastward against Taurus, 8.4° to the upper left of Aldebaran and 11.0° to the upper right of Elnath, the next bright star in the conjunction sequence.

Chart Caption – 2023, February 8: After twilight ends, Mars is visible against Taurus.

Wait until the sky darkens further, but before the moon rises nearly four hours after sundown, to see Mars against Taurus’ backdrop. In urban and suburban settings, a binocular helps find the dimmer stars.  Aldebaran and the Hyades star cluster make a letter “V” that is the Bull’s head.  The Pleiades star cluster, also known as the Seven Sisters, rides on the Bull’s back.  Elnath and Zeta Tauri, dot the horn’s tips.

After Mars passes Elnath on March 9th, it moves between the horns two nights later.  Then on the 14th it passes Zeta Tauri, marching into Gemini on March 26th.

Chart Caption – 2023, February 8: Four hours after sundown, the gibbous moon is low in the east, near the star Zavijava.

By four hours after sundown, the gibbous moon is over 10° above the east horizon.  It is over 11° to the lower right of Denebola and 2.3° to the left of Zavijava, in Virgo.  The second star is likely overwhelmed by the moon’s brightness.  To see it, block the moon’s glare with your hand or the edge of a building.

Check the moon’s location compared to Zavijava in the morning before daybreak, to see how the lunar orb moves through its orbital path compared to the sidereal background.



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