2023, October 2: Goodbye, Mercury, Moon-Pleiades Conjunction

Photo Caption – Venus, Jupiter, Mars, Regulus, 2015, October 15


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:49 a.m. CDT; Sunset, 6:31 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

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, October 2: Three hours after sunset, Jupiter and the moon are in the eastern sky.

Saturn is challenging to see low in the west-southwest, over three hours before sunrise, when Venus rises.

One hour before sunrise, the bright moon, 88% illuminated, is over halfway up in the west-southwest, 5.8° above Jupiter.  During the past few mornings, the lunar orb hopped eastward each morning as it approached the Jovian Giant.  This morning, the moon is east of the planet.

Jupiter is retrograding in front of Aries, 13.0° to the left of Hamal, the constellation’s brightest star.

Chart Caption – 2023, October 2: Uranus is in the same binocular field with the gibbous moon, a challenging view.

Uranus is in the same binocular field with the moon this morning.  This is a challenging view because of the bright moonlight, but not a lost effort like the view of Neptune a few mornings ago.  Four distant stars assist with aligning the binocular with the sky.  They are Delta Arietis (δ Ari on the chart), Zeta Arietis (ζ Ari), Tau Arietis (τ Ari), and 63 Arietis (63 Ari). Place the moon at about four o’clock on the circular field near the edge of the field of view. The four brighter field stars are near the upper right.  Then Uranus is off-set to the upper left of the center.  It is dimmer than the reference stars. Reduce the moon’s glare by slightly moving the binocular so that the moon is outside the lower right portion of the field.

Chart Caption – 2023, October 2: Venus, Mercury, and Regulus are in the eastern sky during morning twilight.

Mercury is quickly leaving the eastern sky after its best morning appearance of the year.  The speedy planet is bright enough to be seen, but it is only 3° above the horizon and over 25° to the lower left of Regulus, Leo’s brightest star, at 45 minutes before sunrise.  This may be the last morning to see it without an optical assist.  Find a location with a clear horizon looking toward Mercury’s direction, such as an elevated structure or hilltop. For several more mornings, follow it into the morning sky with a binocular. So, for this appearance, we say, “Goodbye, Mercury!”

Brilliant Venus is over 30° up in the east-southeast, 6.3° to the upper right of Regulus.  Venus passes the star October 9th.  This morning through a binocular, the Morning Star is 1.0° to the upper left of Omicron Leonis (ο Leo on the chart).  During the next week, watch Venus close the gap to Regulus.

Evening Sky

The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. (NASA)

Mars is not visible as it sets about 35 minutes after sunset. 

Chart Caption – 2023, October 2: Saturn is in the southeast, during the early evening, in front of Aquarius, near Skat and Lambda Aquarii (λ Aqr).

Saturn rises before sunset and it is over 20° above the southeast horizon, one hour after sundown. Saturn is not as bright as Venus or Jupiter, but it is brighter than most stars in the sky this morning.

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

Saturn retrogrades in front of Aquarius, 10.1° to the upper right of Skat, the leg, and 10.6° to the right of Lambda Aquarii (λ Aqr on the chart).  During the night, Saturn appears farther westward. About four hours after sundown, the Ringed Wonder is in the southern sky.  It sets about three hours before sunrise, about the time Venus rises.

Saturn is very low in the west-southwest when Venus rises.  Theoretically, they are visible in the sky at the same time, brilliant Venus in the east and Saturn in the west-southwest.  The atmosphere near the horizon blurs and dims celestial objects.  Likely Saturn is visible with a binocular.  On the 10th, Venus rises as Saturn sets.  Afterward, Saturn sets before Venus rises.  The two planets are again in the sky at the same time during early spring of 2024.

Chart Caption – 2023, October 2: Three hours after sunset, Jupiter and the moon are in the eastern sky.

Bright Jupiter rises in the eastern sky two hours after nightfall.  An hour later, it is nearly 20° up in the east, over 15° to the upper right of the gibbous moon, 83% illuminated.

Chart Caption – 2023, October 2: Through a binocular the bright moon is near the Pleaides star cluster.

The Pleiades star cluster is 2.2° to the upper left of the lunar orb.  It is mostly washed out by the moonlight.  The cluster and the moon are in the same binocular field, although the moon’s light may leave a temporary afterimage in vision, like that from a camera flash.  To see the cluster, move the binocular slightly so the moon is outside the field of view while the stars are still visible.

Photo Caption – Jupiter (NASA Photo)

Through a telescope, at 10:53 p.m. CDT, Jupiter’s Great Red Spot is at the center of the planet in the southern hemisphere.  Europa is visible against the planet’s globe to the lower left of the long-lived atmospheric disturbance.  The satellite’s shadow is near the edge of the planet to the lower right of the spot.

As the calendar day ends, Jupiter is less than halfway up in the east-southeast, with the moon to its lower left.  By tomorrow morning the planet is in the west-southwest.


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