May 30, 2023: After sundown and throughout the night, the gibbous moon is near Spica. Venus and Mars dance with stars in the western sky after nightfall.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:19 a.m. CDT; Sunset, 8:18 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:
One hour before sunrise, two bright planets are in the eastern sky. Bright Jupiter is over 6° above the horizon. Its slow emergence from bright twilight continues. The planet outshines all other stars in the sky.
Notice Capella, slightly lower than Jupiter, in the north-northeast. This star appears in the northwest after sundown, sets during the night, and rises over two hours before daybreak. After Jupiter, Capella is only dimmer than Arcturus and Vega this morning.
In addition to Capella, notice Mirfak (Perseus) and Hamal (Aries).
Saturn, dimmer than Jupiter, is nearly one-third of the way up in the sky above the southeast horizon. It is nearly 20° to the upper left of the star Fomalhaut, meaning “the mouth of the southern fish.”
One day after its greatest elongation, Mercury seems to struggle to emerge from the sun’s bright light. Thirty minutes before the sun rises, the speedy planet is less than 5° above the east-northeast horizon and 11.3° to the lower left of Jupiter. The separation is too great for both to fit into the same binocular field of view.
Mercury is brightening but is visible only with optical assistance. The morning twilight is too bright to see it without the assist.
One hour after sundown, the bright gibbous moon, 82% illuminated, is less than halfway up in the south and 6.1° to the upper right of Spica, meaning “the ear of corn” and Virgo’s brightest star. The next Full moon occurs June 3rd at 10:42 p.m. CDT.
The Venus-Mars planet show continues in the west during the evening. At this hour brilliant Venus is less than one-third of the way up in the sky. Simply described, it is “that bright star” in the west. It is over fifty times brighter than Capella, the next brightest star in the sky this evening.
Through a telescope, Venus shows a phase that is slightly gibbous, 52% illuminated. The planet is nearing greatest elongation from the sun and a half-lit phase. The planet continues to brighten as it overtakes our planet and the phase diminishes.
Venus is stepping eastward in front of Gemini’s distant stars, 4.2° to the lower left of Pollux, a Gemini Twin. The planet passed the star last night. During the next few evenings watch it move into alignment with Castor, the other Twin, and Pollux. Draw an imaginary line starting at Castor and extend it through Pollux. Venus approaches and crosses that line on subsequent evenings. The nightly change is easy to spot. Venus is heading toward Mars, 11.4° to the upper left.
Mars is marching eastward in front of Cancer’s dim stars. It continues to fade in brightness and it is about the brightness of Castor. Through a binocular it is near the Beehive star cluster. In a few nights, the planet appears to pass through the stellar bundle. Even with a binocular, the dimmer stars in the cluster are whitewashed by the bright moon. Wait until near the end of twilight to see the sky darker, but illuminated by moonlight.
The Beehive is also known as the Praesepe or manger. Notice the two celestial donkeys, Asellus Borealis and Asellus Australis, in the same binocular field with the star cluster.
Continue to watch Venus and Mars step eastward each evening.
- 2023, December 20: Morning Star, Evening Moon Nears JupiterDecember 20, 2023: Brilliant Venus is in the southeast before daybreak. After nightfall the gibbous moon nears Jupiter in the southeast sky.
- 2023, December 19: A Scorpion Fumble, Moon MidwayDecember 19, 2023: Before sunrise, Venus appears below the Scorpion’s claws. After sundown, the moon is nearly midway from Saturn to Jupiter.
- 2023, December 18: Pinched VenusDecember 18, 2023: Look for Venus between the Scorpion’s claws in the southeast before sunrise. The thick crescent moon is in the evening sky with Jupiter and Saturn.
- 2023, December 17: Celestial PairsDecember 17, 2023: Before sunrise, Venus passes Zubenelgenubi, a planet-star conjunction. After sundown, Saturn and crescent moon are paired, a planet-moon conjunction.
- 2023, December 16: Venus Clawed, Evening Crescent Nears SaturnDecember 16, 2023: Before daybreak, Venus is above the Scorpion’s southern claw. After nightfall, the crescent moon nears Saturn.