2023, August 10: Look for Perseids, Morning Crescent Moon


August 10, 2023: With a waning moon look for Perseid meteors before the beginning of morning twilight.  The morning crescent moon is near Aldebaran, Taurus’ brightest star.

Photo Caption: April 25, 2018: Venus and Sirius


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:54 a.m. CDT; Sunset, 7:58 p.m. CDT.  Check local sources for sunrise and sunset times.

2020, August 14: Sirius clears the horizon minutes before sunrise. The star is visible through binoculars and a short time exposure, but not with the unaided eye.

Sirius is appearing for sky watchers at 40° north latitude.  Look low in the east-southeast about 45 minutes before sunrise.  The date of the first appearance depends on local weather and obstructions along the horizon.

Chart Caption – 2023, August 10: Procyon is making its first morning appearance at Chicago’s latitude.

At Chicago’s latitude, Procyon, the Little Dog Star, is making its first appearance, signaling that Sirius is not far behind. The star’s name means “before the dog,” because it rises about 20 minutes before Sirius or makes its first morning appearance a few days before the Dog Star. At forty minutes before daybreak, look for Procyon low in the eastern sky above the horizon, over 25° to the lower left of Betelgeuse, Orion’s bright star.  Use a binocular to initially locate the stars in the brightening approach of daytime.

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)

The Perseid meteor shower peaks before twilight begins in three mornings.  The shower is improving in its rate, as well as a dimmer crescent moon contributing less moonlight.  The shower is best spotted after midnight as the shower’s radiant rises higher in the sky.  The shower peaks on the 13th before twilight begins. More meteors can be seen looking overhead, but shooting stars can be seen anywhere in the sky.

Summaries of Current Sky Events

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, August 10: Jupiter and the moon are in the eastern sky before daybreak.

A crescent moon, 30% illuminated, shines from the eastern sky during morning twilight, 8.6° to the upper left of Aldebaran, Taurus’ brightest star, and nearly 30° to the lower left of bright Jupiter.

Photo Caption – Venus and the crescent moon. Notice the “earthshine” on the night portion of the moon.

Begin looking for earthshine on the moon’s night portion.  This effect is from sunlight reflecting from Earth’s oceans, clouds, and land.  It grows each morning as the moon wanes and the crescent thins.

Photo Caption – Jupiter (NASA Photo)

At 4:15 a.m. CDT, Jupiter’s Great Red Spot is at the center of the planet in the southern hemisphere when viewed through a telescope.

Use a binocular to explore two star clusters, the Pleiades and the Hyades.  Aldebaran and the Hyades make a sideways “V” that forms the Bull’s head.

Capella, the fourth brightest star seen from the mid-northern latitudes, is about the same altitude – height above the horizon – as the crescent moon and over 20° to the left.

Chart Caption – 2023, August 10: Saturn is in the southwest during morning twilight.

At an hour before daybreak, Saturn is over 25° above the southwest horizon.  It is dimmer than might be expected for a planet when considering Jupiter, Venus, and, sometimes, Mars.  The Ringed Wonder is brighter than most of the stars this morning.

Chart Caption – Saturn’s retrograde – apparent westward movement compared to the distant stars – is depicted during four and one-half months.

Saturn is retrograding in front of Aquarius.  The stars are dim and washed out by outdoor lighting in urban and suburban settings. 

Use a binocular to find Skat, 7.6° to the left of Saturn, and 6.9° to the lower right of Lambda Aquarii (λ Aqr on the chart). Retrograde is an illusion from our planet moving between the sun an outer planet.

Evening Sky

Photo Caption – This picture of Venus was taken by the Galileo spacecraft (NASA)

The three evening planets – Venus, Mercury, and Mars – are in bright twilight.  Venus is nearing its inferior conjunction and a journey into the morning sky.

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

Mercury, an evening after its greatest elongation, sets an hour after sunset.  Thirty minutes earlier it is less than 5° above the western horizon, a very challenging view with the planet’s fading brightness.

Photo Caption – NASA’s Hubble Space Telescope photographed Mars on July 18, 2018, during a dust storm and near its closest approach to Earth since 2003. (NASA photo)

Mars, dimmer than Mercury, sets about eighty minutes after the sun.  Finding it is a lost cause.  It is slowly sliding into evening twilight, setting one to two minutes earlier each night.  The planet passes behind the sun during November and returns to the morning sky during 2024.

Chart Caption – 2023, August 10: Nearing opposition, Saturn is in the east-southeast two hours after sunset.

Saturn, nearing opposition, rises earlier each evening.  It appears above the east-southeast horizon, forty-four minutes after sundown.  Over an hour later, the Ringed Wonder is over 10° above the horizon.

Photo Caption – Celebrate astronomy with local astronomy clubs. AI-generated telescopes during evening twilight. (Credit: Open AI)

With Saturn entering the evening sky, look for public telescope events sponsored by science museums and local astronomy clubs for next month and during October to see Saturn through a telescope.  Or talk with your neighborhood sky watcher about viewing the planet through their telescope. During September and October, the sun sets earlier and Saturn is higher in the sky after sundown.

Saturn slowly appears farther westward during the night, from Earth’s rotation. Find it tomorrow in the southwest. Jupiter follows Saturn across the horizon less than three hours later and appears high in the eastern sky during morning twilight.



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