2023, October 22: Moon Approaches Saturn

Predawn Eastern Sky, October 22, 2013
Chart Caption – Predawn Eastern Sky, October 22, 2013


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 7:11 a.m. CDT; Sunset, 5:59 p.m. CDT.  Check local sources for sunrise and sunset times. Times are calculated by the US Naval Observatory’s MICA computer program.

Summaries of Current Sky Events
Summary for Venus as a Morning Star, 2023-24

See this week’s highlights article.

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, October 22: Venus is with Leo in east-southeast before sunrise.

Venus and Jupiter shine brightly during October mornings this year.  Brilliant Venus, one day before greatest elongation, stands about 30° up in the east-southeast, one hour before sunrise.  Simply described, it is “that bright star” in the eastern sky before sunrise.

The planet steps eastward in front of Leo, a westward-facing Lion. It passed Regulus, the figure’s brightest star on October 9th, and Rho Leonis (ρ Leo on the chart) a week later.  Tomorrow, it has a wide conjunction, nearly 10°, with Chertan.

Chart Caption – 2023, October 22: Jupiter is in the western sky before daybreak, nearly between Hamal and Menkar.

At this hour, bright Jupiter is in the western sky.  It retrogrades, appears to move westward against the starfield, in front of Aries, 12.1° to the left of Hamal, the constellation’s brightest star.

Chart Caption – Jupiter’s retrograde motion against the starfield is demonstrated for 2023.

Retrograde motion is an illusion.  Earth is overtaking distant Jupiter on an inside orbital track.  As our faster moving planet moves between the Jovian Giant and the sun, the more-distant world seems to backup or move westward compared to the stars.  Jupiter does not back up in its orbit, rather the line of sight from Earth through Jupiter that extends toward the starfield shifts westward, when it normally points eastward toward the stars.

In less than a week, Jupiter moves between Hamal and Menkar, part of Cetus.

Evening Sky

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

Mercury is moving into the evening sky, but this evening it sets only five minutes after the sun.  Similarly, Mars is immersed in bright twilight, setting seventeen minutes after Mercury, but Mars is moving toward solar conjunction during mid-November and entry into the morning sky.  Mercury passes Mars before sunrise January 27, 2024.  Venus passes the Red Planet about a month later.

Chart Caption – 2023, October 22: The gibbous moon approaches Saturn after sundown.

This evening the gibbous moon approaches Saturn.  The lunar orb is nearly 24° up in the south-southeast at one hour after sundown, 20.6° to the lower right of the Ringed Wonder.

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

Saturn is not as bright as Venus or Jupiter, although it outshines most stars in the sky tonight.  Like Jupiter, Saturn is retrograding against Aquarius.  Earth passed between Saturn and the sun during August, but the line of sight through Saturn to the stars continues to move westward.  The effect ends November 4th.

In this moonlight, use a binocular to see Deneb Algedi, Capricornus’ tail, 6.8° to the right of the planet.

As Earth rotates during the night, Saturn is in the south three hours after sunset.  It sets in the west-southwest five hours before sunrise, nearly two hours after moonset, and an hour before Venus rises.

Chart Caption – 2023, October 22: Jupiter is in the east, two hours after sunset.

At this hour, Jupiter is low in the east-northeast, nearly 5° above the horizon.  By two hours after sundown, the Jovian Giant is over 15° above the eastern horizon.  By midnight, the planet is in the southeast and by tomorrow morning, it is in the western sky.


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