2023, March 31: Morning Saturn, Evening Bright Gibbous Moon


March 31, 2023: Saturn is visible in the east-southeast before sunrise.  Three planets – Venus, Mercury, and Mars – are in the sky with the gibbous moon during the night.

Photo Caption – 2020, May 2: The three morning planets span over 25°. Jupiter and Saturn are 4.8° apart.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:36 a.m. CDT; Sunset, 7:15 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.

March ends with twelve hours, thirty-nine minutes of daylight, gaining 74 minutes of daylight during the month.

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, March 31: Saturn is low in the east-southeast before daybreak.

Forty-five minutes before sunrise, Saturn is nearly 6° above the east-southeast horizon.  It is emerging from brighter twilight into a darker sky.  It rises nearly eighty minutes before daybreak and 2-3 minutes earlier, compared to sunrise, each day.

Saturn is typically the dimmest of the five bright planets.  This morning it is the fourth brightest starlike body, dimmer than Arcturus, Vega, and Altair, but slightly brighter than Spica.

Evening Sky

Chart Caption – 2023, March 31: Venus and Mercury are in the west after sundown.

Jupiter, moving toward solar conjunction on April 11th, sets less than forty minutes after sundown.

A few minutes later, Venus is over 25° above the western horizon.  It continues to step eastward against Aries.  It is over 13° to the upper left of Hamal, the constellation’s brightest star, although the star is about the brightness of the Big Dipper’s stars.  Look carefully for it.

The Pleiades star cluster is over 12° above Venus and the general direction for Venus’ eastward trek against the stars.  The planet moves into Taurus on April 7th, passing the cluster three nights later.

Chart Caption – 2023, March 27-April 1: Venus moves through the same binocular field with Uranus.

Through a binocular, Venus is still in the same field of view with Uranus, 1.8° to the brilliant planet’s lower left.  For most sky watchers Uranus is not visible to unassisted vision.  In a location free from the perpetual intrusion of outdoor lighting, the planet is visible without optical help.  Additionally, tonight’s bright moonlight washes out the dimmer stars and other celestial wonders.

Through the binocular, place Venus off-center to the upper right of the field of view.  Uranus is to the lower left.  It appears as an aquamarine star.  The brightness difference is considerable.  The Evening Star is over 8,000 times brighter than Uranus.

Mercury continues to emerge from bright twilight.  At this hour, it is nearly 5° above the western horizon, over 22° to the lower right of Venus.  Find an observing location with a clear western horizon.

Chart Caption – 2023, March 31: The bright gibbous moon is between Pollux and Regulus.

The gibbous moon, 78% illuminated, is high in the southeast, in front of Cancer’s faint stars.  It is midway from Pollux to Regulus, meaning “the prince,” the brightest star in Leo. The somewhat empty space between them is Cancer.

Chart Caption – 2023, March 31: The moon is at Castor’s foot.

Mars is between the moon and Venus.  Growing dimmer from Earth’s increasing distance to the planet, it is high in the west-southwest at Castor’s foot.

Notice that Mars is 3.7° to the right of Tejat Posterior, commonly known as Castor’s heel.  The planet passes the star on April 5th.

Chart Caption – 2023, March 26-April 5: Mars moves through the same binocular field with Propus and Messier 35 (M 35).

Through a binocular, Mars appears with the heel star, the toe (Propus) and a star cluster catalogued as Messier 35 (M 35 on the chart).  The stellar bundle is partly washed out by the bright moonlight.  Mars is 1.6° above the cluster.



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