2023, April 17: Look for the Thin Crescent Moon, Venus Stepping Through the Bull


April 17, 2023: A very thin crescent appears in the eastern sky to the lower left of Saturn before sunrise.  Venus steps eastward through the Bull after sundown.  Mars marches in Gemini, while Mercury fades into twilight.

Photo Caption – Crescent moon, February 27, 2022.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:08 a.m. CDT; Sunset, 7:34 p.m. CDT.  Check local sources for sunrise and sunset times for your location.  Times are calculated by the U.S. Naval Observatory’s MICA computer program.

Summaries of Current Sky Events

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, April 17: Saturn and the lunar crescent are in the eastern sky before daybreak.

Saturn continues its entry into the morning sky.  At forty-five minutes before sunrise, the Ringed Wonder is over 10° above the east-southeast horizon.  The planet is not bright like Venus or Jupiter, but it is among the brightest “stars” in the sky this morning.

At this hour, the crescent moon, 9% illuminated, is very low in the east and over 15° to Saturn’s lower left.  Find a very clear horizon to the east and use a binocular to find the crescent.  A hilltop or elevated structure provide clear views across any obstacle.  A large body of water provides a natural horizon to make this observation.

Track the moon as it rises higher during brighter twilight.  Eventually sunlight overwhelms the lunar light.

Jupiter is slowly entering the morning sky after its solar conjunction.  It becomes visible next month in the east before daybreak.

Evening Sky

Chart Caption – 2023, April 17: Venus and Mercury are in the western sky after sundown.

Brilliant Venus is “that bright star” in the western sky after sunset.  It steps eastward against Taurus.  This evening it is 7.6° to the upper right of Aldebaran, the Bull’s brightest star, and 7.9° to the upper left of the Pleiades star cluster.

Chart Caption – 2023, April 17: Through a binocular, Venus appears near the outlying stars of the Hyades.

Inspect the region of the sky near Venus with a binocular.  The Hyades cluster is to the lower left and the Pleiades are to the lower right. The Evening Star is in a rich starfield with several stars without formal names, but are catalogued with Greek letters. Epsilon Tauri (ε Tau on the chart) is at the top of the “V” of Taurus, opposite Aldebaran and part of the main concentration of the Hyades star cluster.  The planet is to the lower right of Kappa Tauri (κ Tau) and Upsilon Tauri (υ Tau), Hyades’ outliers.  It passes them tomorrow evening.  Venus is headed toward Tau Tauri (τ Tau), passing nearby in four nights.

At forty-five minutes after sundown, Mercury, nearly 25° to the lower right of Venus, is less than 9° above the west-northwest horizon.  Now past prime viewing, the planet is fading quickly into evening twilight.  At this brightness, use a binocular to locate the planet.  Can you find it without the optical assist?

Chart Caption – 2023, April 17: Mars is to the upper left of Mebsuta and below Castor and Pollux during the evening hours.

The final bright planet tonight is also fading in brightness, but not like Mercury.  Mars, about 35° to the upper left of Venus, is high in the west-southwest at this hour and below the Gemini Twins, Castor and Pollux.

The Red Planet is marching eastward in front of Gemini’s stars, 1.7° to the upper left of Mebsuta and nearly 12° below Castor.

Wait until twilight ends about 90 minutes after sunset, when Gemini’s dimmer stars are visible.  The pattern resembles two stick figures with an arm around the other’s shoulders.

Each evening Mercury continues to fade from view.  Continue to watch Venus step through the Taurus starfields, seeming to chase after Mars, marching eastward in Gemini.



Leave a Reply Cancel reply