2023, July 13: Gorgeous Moon-Pleaides Conjunction, Evening Planet Dance


July 13, 2023: Before sunrise, the moon pairs with the Pleiades star cluster in the eastern sky.  After sunset, Venus and Mars continue their dance with Regulus.

2020, July 17: The crescent moon is in a group with Venus and Aldebaran as the Pleiades appear above the scene during early morning twilight.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:27 a.m. CDT; Sunset, 8:25 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, July 13: The moon appears near the Pleiades star cluster before sunrise. Bright Jupiter is to the upper right.

During morning twilight, the crescent moon, 17% illuminated, appears 2.5° below the Pleiades star cluster before sunrise. An hour before daybreak, find the moon nearly 30° above the east horizon. For more easterly sky watchers, the moon is closer to the stellar bundle.

The moon is showing earthshine, reflected sunlight from Earth’s oceans, clouds and land.  That light gently lights up the lunar night.  This effect can be captured with a tripod-mounted camera and a time exposure up to a few seconds.

Chart Caption – 2023, July 13: The moon appears near the Pleiades star cluster before sunrise. Bright Jupiter is to the upper right.

The moon and star cluster easily fit into the same binocular’s field of view.  Earthshine is accented by the binocular and perhaps two dozen stars are visible in the sight.

Photo Caption – 2022, August 19: Mars, the moon, and Pleiades,

Depending on the camera’s settings, several seconds may be needed to capture the Pleiades with the moon and Earthshine that is overexposed.  The photo above is a composite of an eight-second exposure at ISO 200 that included the Pleiades, Mars, and an overexposed moon and a one-two hundred-fiftieth of a second exposure that captured a clear view of the moon, but Mars and the Pleiades are too faint to be captured.

The moon is visible with the Pleiades each month, but for the next few months, the phase is brighter and overwhelms the dimmer cluster. Beautiful and photogenic crescents appear with the star cluster on March 14th and April 11, 2024.

Bright Jupiter, nearly 40° up in the east-southeast, is to the upper right of the moon-Pleiades scene.  The planet is gently moving eastward in front of Aries dim stars.

Chart Caption – 2023, July 13: Saturn is in the south during morning twilight.

Saturn, dimmer than Jupiter, is less than 40° up in the south, 12.8° to the upper left of Deneb Algedi, in Capricornus, and 19.6° to the upper right of Fomalhaut, the mouth of the southern fish.  The Ringed Wonder is retrograding, appearing to move westward against the distant starfield.

Evening Sky

Chart Caption – 2023, July 13: Venus, Mars, and Regulus are in the western sky after sundown.

The evening planet dance continues in the west after sundown.  Brilliant Venus, in its interval of greatest brightness, is easily visible as night falls.  It is “that bright star” showing through western twilight.  Three nights ago, Venus and dimmer Mars bunched with the star Regulus, their closest grouping until 2053. 

This evening, Mars is marching away from the Evening Star and Regulus.  Venus slows before its near or quasi-conjunction in three nights with Regulus.  Then the planet reverses its direction on the 22nd and begins to retrograde.  It passes between Earth and the sun on August 13th, then moves into the morning sky.

Chart Caption – 2023, July 13: Venus, Mars, and Regulus appear in the same binocular field of view during the early evening.

Venus sets three to four minutes earlier each evening, setting ninety-seven minutes after sundown tonight.  Begin looking about 45 minutes after sundown with a binocular to find Mars and Regulus.  Fifteen minutes later, Venus is less than 10° above the western horizon.  Find a clear view in that direction.

Regulus, the brightest star in Leo, is 3.6° to the upper left of Venus and 2.1° to the lower right of Mars.

Mars is fainter than might be expected.  It has dimmed considerably since its close approach to Earth nearly nine months ago.  This evening it is over four times farther away and dimmer than when closest.

This planet dance continues as Venus and Mars disappear into bright evening twilight.  Mercury is racing into the evening sky.  Tonight, the speedy planet sets fifty-five minutes after the sun.  The moon moves through on the 19th and 20th, creating a traffic jam of planetary bodies in the western evening sky.

Continue to watch this evening planet shuffle.



Leave a ReplyCancel reply