July 12, 2023: Summer begins on Mars today. The morning crescent moon appears between Jupiter and Pleiades. Venus and Mars dance with Regulus after sundown.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:26 a.m. CDT; Sunset, 8:26 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.
Summer begins in the Martian northern hemisphere today. The seasons are from a tilt of 25°, similar to Earth’s. Long duration Martian explorers would see the sun rising and setting at different locations along the horizon with a high summer sun and a low winter sun.
The season lasts 183.46 Earth days or 178.56 Martian sols, the name for the day-night cycle on the Red Planet. The sol is 24 hours, 39 minutes, 35 seconds. Autumn arrives on Earth date January 12, 2024.
Summer temperatures can rise to 70° F, but with very little atmosphere, and what little air exists, is primarily carbon dioxide. Dust storms can create reddish skies and sunsets. Happy Martian Solstice!
Summaries of Current Sky Events
SUMMARY FOR VENUS AS AN EVENING STAR
Here is today’s planet forecast:
The crescent moon this morning is between Jupiter and the Pleiades star cluster. One hour before sunrise, the moon, 26% illuminated, is over 30° up in the east, 7.9° to the lower left of Jupiter.
Look carefully for the Pleiades, nearly 12° to the lower left of the moon. The cluster resembles a tiny dipper and may initially catch your eye when looking at the thinning crescent and bright Jupiter. Tomorrow morning the crescent moon is near the cluster.
Look for earthshine on the night portion of the moon. This is from sunlight reflected from Earth’s oceans, clouds and land that gently lights up the lunar night.
The Pleiades are part of Taurus. The Bull’s brightest star, Aldebaran, is below the star cluster and nearly 15° above the horizon.
Jupiter’s Great Red Spot is at the center of the planet in the southern hemisphere at 5:13 a.m. CDT, but it is visible across the Americas through a telescope earlier when it first enters the view from Jupiter’s rapid rotation.
Saturn, considerably dimmer than Jupiter, is nearly 40° above the southern horizon and west of the south cardinal direction. The planet continues to retrograde – appear to move westward against the distant stars – in front of dim Aquarius, nearly 13° to the upper left of Deneb Algedi, in Capricornus, and nearly 20° to the upper right of Fomalhaut, the mouth of the southern fish.
Venus continues to sparkle in the western evening sky. Still in its interval of greatest brightness, the planet’s visual intensity easily overwhelms all other starlike bodies in the sky. The planet is easy to locate as night falls.
The Evening Star sets three to four minutes earlier each evening. This evening it leaves the sky one hundred minutes after sundown.
Through a telescope, the planet is featureless from its veil of thick clouds. It shows a crescent that is 22% illuminated. The planet’s phases resemble Moon phases, but different terms are used from waxing and waning. The cycle of phases appears differently from the moon’s phases. To name them the shape and the time when the planet appears are used. Tonight’s Venusian phase is evening crescent.
Venus continues to approach the star Regulus. The gap is 3.8°, with the planet to the lower right of the star. Mars is 1.6° to the upper left of Regulus. The trio is nearly in an imaginary line. Venus closes to 3.5° in four nights in a near or quasi-conjunction. Venus seems to be ducking under or south of Regulus, but there is no conjunction. On the 22nd, Venus reverses its course and begins to retrograde.
Use a binocular to initially locate Regulus and Mars. Can you see them without the optical assist?
Venus is overtaking our planet on an inside orbital path that carries it around the sun every 225 days. This evening it is 38 million miles away and closing in. When Venus passes between Earth and the sun in a month, its distance is 27 million miles.
Mercury races into the evening sky to join Venus and Mars, although it is visible during brighter twilight. On the 19th and 20th, Venus, Mercury, Mars, and the crescent moon create a planetary traffic jam in the western sky.
Each evening watch Mars march away from Venus and Regulus and the Evening Star slows as it nears retrograde.
- 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.