June 26, 2023: Evening Star Venus approaches its interval of greatest brightness. It is that bright star in the west after sundown. Mars is nearby, while Jupiter and Saturn are in the morning sky.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:17 a.m. CDT; Sunset, 8:30 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.
This is the fourth evening of eight nights when the latest sunset occurs.
Summaries of Current Sky Events
Here is today’s planet forecast:
An hour before sunrise, Saturn is about 35° above the south-southeast horizon. Compared to Venus and Jupiter, Saturn is unexpectantly dim, but brighter than most stars in the sky this morning.
Saturn rises over five hours before the sun, over three hours before the beginning of morning twilight. This places the planet in the southern sky before sunrise.
Saturn is retrograding in front of dim Aquarius. Retrograde motion is an illusion as our faster moving planet overtakes and passes between the sun and the slower-moving outer planet. The line of sight, that normally moves eastward against the distant starfield, shifts westward. Neither planet changes their direction in their respective orbit.
The star Fomalhaut, meaning the mouth of the southern fish, is about halfway from the horizon to Saturn.
Bright Jupiter is farther eastward, nearly 25° above the horizon. The Jovian Giant is moving eastward against Aries, 11.1° to the lower right of Hamal, the constellation’s brightest star.
The slightly gibbous moon, 58% illuminated, is over 35° up in the southwest at one hour after nightfall. It rises in the early afternoon and can be easily seen in a clear sky during the daytime.
The lunar orb is 10.6° to the upper right of Spica, Virgo’s brightest star and 4.0° to the lower left of Porrima, also known as Gamma Virginis. Use a binocular to spot Porrima in this bright moonlight.
Notice that the moon casts shadows on the ground. This moonlight effect is the same that occurs on the moon from earthshine, reflected sunlight from Earth’s features.
The planet show continues in the western sky at this hour. Brilliant Venus, approaching its interval of greatest brightness, is that bright star in the west as the sky darkens. When looking for the moon this evening, Venus is about 15° up in the west, considerably lower than it was a month ago. It sets two to three minutes earlier each evening compared to sundown.
The Evening Star’s interval of greatest brightness begins in three nights and lasts through July 17th. The midpoint is July 8th. The planet continues to brighten slightly to approximately the midpoint date, but the change is not likely detectible without light measuring equipment.
NASA’s Jet Propulsion Laboratory, known as JPL, predicts that Venus reaches its greatest brilliancy or brightest point on July 12th. Notice that the articles here use the term greatest brightness to name an interval of nights when the planet appears brightest to the unaided eye, while greatest brilliancy marks a few hours when the planet is actually brightest as measured with light measuring equipment.
This evening Venus steps into Leo, 3.8° to the lower right of Mars and 12.0° to the lower right of Regulus. Venus’ eastward rate is slowing and it does not catch Mars. In four evenings, a near conjunction or quasi-conjunction occurs with the Red Planet when the separation is 3.6°. Mars marches away from Venus, while Earth’s Twin planet continues to slow as it nears Regulus. A quasi-conjunction occurs with the star on July 16th, with a separation of 3.5°. Venus finally passes Regulus on October 9th, after they move into the morning sky.
- 2023, October 21: Three Bright Planets, First Quarter MoonOctober 21, 2023: Venus, Jupiter, and Saturn are easy to locate during nighttime hours. The First Quarter moon phase occurs this evening.
- 2023, October 20: Jupiter’s Double Shadows, Mercury at Superior ConjunctionOctober 20: After midnight, Jupiter’s moons’ shadows dance across the cloud tops. Mercury is at superior conjunction.
- 2023, October 19: Poured Moon, See Planet UranusOctober 19: Sagittarius seems to pour the moon into the sky this evening. Find Uranus with a binocular.
- 2023, October 18: Moon-Antares Conjunction, Bright PlanetsOctober 18, 2023: The moon is near Antares after sunset. Venus, Jupiter, and Saturn are in the sky during the nighttime hours.
- 2023, October 17: Scorpion MoonOctober 17, 2023: The crescent moon is with Scorpius during evening twilight. Venus and Jupiter gleam from the predawn sky.