2023, August 13: Perseid Shower at its Best, Venus at Inferior Conjunction


August 13, 2023:  The Perseid meteor shower peaks before twilight begins this morning.  Venus passes between Earth and Sun and into the morning sky.

In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower Friday, Aug. 12, 2016 in Spruce Knob, West Virginia. Photo Credit: (NASA/Bill Ingalls)


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:57 a.m. CDT; Sunset, 7:54 p.m. CDT.  Check local sources for sunrise and sunset times.

Photo Caption – A Perseid meteor, photographed with a camera that views the entire sky. (NASA photo)

The Perseid meteor shower peaks before twilight begins this morning.  The shower’s origin is the dust and debris from Comet 109P/Swift-Tuttle.  The sun’s light vaporizes the comet’s ices, releasing dust particles that are widely distributed along the orbital path. 

Each year, Earth passes through the debris, the dust enters the atmosphere, and vaporizes around 50 miles above the ground. The shower’s center or radiant is in Perseus.  It rises high in the sky from Earth’s rotation after midnight when we view the meteor shower head-on.

The predicted maximum visible rate before sunrise is ninety meteors per hour.  What is seen depends on the sky darkness and how much of the sky is visible to any single meteor watcher. Urban and suburban sky watchers may see approximately ten meteors each hour, while those in the countryside might see twenty to thirty per hour.

After tonight, the shower continues, although the rate diminishes.

Chart Caption – 2023, August 13: Venus is at inferior conjunction between Earth and the sun.

Venus passes between Earth and Sun today, known as inferior conjunction.  The planet quickly moves into the morning sky, west of the sun, rising nearly two hours before the sun at month’s end.

From approximately September 10th through October 1st, Venus and Sirius are approximately the same altitude above the eastern horizon.  Venus does not pass Sirius, because the night’s brightest star, is not near the ecliptic, the plane of the solar system, where Venus moves. They are over 40° apart in the sky.

Summaries of Current Sky Events

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, August 13: Jupiter is in the southeast before sunrise.

Bright Jupiter is high in the southeast an hour before sunrise.  It moves eastward in front of Aries, 13.1° to the lower left of Hamal, the constellation’s brightest star, and 11.3° to the upper left of Menkar, Cetus’ nostril.  Look for the Pleiades star cluster to the left of the Jovian Giant.

Photo Caption – Jupiter (NASA Photo)

For those on a Perseid meteor watch, Jupiter’s Great Red Spot is at the center of the planet in the southern hemisphere through a telescope at 1:45 a.m. CDT.

Chart Caption – 2023, August 13: During morning twilight, the moon is near Castor and Pollux.

During morning twilight, the crescent moon, 8% illuminated, is about 20° above the east-northeast horizon.  It is 5.5° to the upper right of Pollux and 5.9° to the lower right of Castor.  The stars are the Gemini twins.

Photo Caption – 2020, September 15: The moon is in the east before sunrise. The thin crescent moon is 6% illuminated.

Look carefully at the moon’s cusps or horns.  The region between them gently glows with earthshine, reflected sunlight from Earth’s oceans, clouds, and land illuminates the night portion of the moon.

Chart Caption – 2023, August 13: Before daybreak, Saturn is in the southwest.

Saturn is farther westward, about 20° up in the southwest.  The Ringed Wonder is retrograding in front of Aquarius, 7.6° to the right of Skat, the Aquarian’s leg, and 7.1° to the lower right of Lambda Aquarii (λ Aqr on the chart).

Use a binocular to see the dim starfield.

Evening Sky

Photo Caption – Mercury as Never Seen Before. (NASA photo)

Mercury is retreating back into bright sunlight, setting tonight fifty-two minutes after the sun.

The Red Planet from the Mars Global Surveyor shows the effects of a global dust storm (NASA)

Mars is slowly sliding into bright twilight, but largely a lost cause to see because it is dim.

Chart Caption – 2023, August 13: Two hours after sunset, Saturn is in the east-southeastern sky.

Saturn rises in the east-southeast thirty-six minutes after sundown.  It is approaching opposition, when Earth is between the planet and the sun. Saturn rises earlier each evening. Jupiter follows Saturn across the horizon less than three hours after the Ring Wonder rises.



Leave a ReplyCancel reply