2023, Evening Sky

2023:  The evening sky has a parade of bright planets, featuring Venus, Saturn, Jupiter, Mercury and Mars.  Venus passes Saturn and Jupiter after sunset, but it does not reach Mars.

PODCAST FOR THIS ARTICLE

by Jeffrey L. Hunt

The chart above from US Naval Observatory data shows the setting time intervals of the bright planets, moon, and bright stars near the ecliptic compared to sunset.  The three phases of twilight are included as well.  The activity is for up to five hours after sunset in the western sky.  The chart does not include the setting locations of the planets.

The rising time intervals of Saturn and Jupiter compared to sunset are included as well.  When one of them rises at sunset it is at opposition.

Conjunctions and near conjunctions of planets are included as well as groupings of the moon, planets and bright stars.

January

Four bright planets are in the sky after sunset – Venus, Saturn, Jupiter, and Mars, although the Red Planet sets after five hours after sunset.  These four planets are visible throughout the month. Around mid-month, The Evening Star sets after the end of evening twilight. This continues until early July. Venus passes 0.4° from Saturn on the 22^nd.  Six planets, including Uranus and Neptune, span about 74° from Venus to Mars. The moon joins Venus and Saturn on the next evening, 7.6° from Venus. The moon is 3.5° from Jupiter on the 25^th.  Saturn sinks quickly and disappears into bright evening twilight near month’s end.

February

With three bright planets in the sky, Venus approaches Jupiter.  Venus passes 0.6° from Neptune on the 15th.  A widefield eyepiece is needed to see both in one telescopic field of view.  On the 20^th, Venus moves to within 10° of Jupiter.  The moon is 6.5° from the Evening Star on the next evening. The moon makes a nice pairing with Jupiter (1.3°) on the 22^nd.

March

Venus passes 0.5° from Jupiter on the 1^st and stays within 10° through the 11^th.  Mercury passes superior conjunction and quickly moves into the evening sky. The moon passes 1.8° from Jupiter on the 22nd and 5.9° from Venus the next evening. Look for a pretty pairing of the moon with the Pleiades on the 25^th.  Use a binocular to look for a Jupiter-Mercury conjunction (1.3°) on the 27^th.  Venus passes 1.2° from Uranus on the 30^th.

April

Mercury reaches its greatest elongation (19.5°) on the 11^th.  Even with a narrow elongation, the ecliptic is near its maximum inclination with the western horizon to give the planet its best evening appearance of the year. Venus moves from Aries into Taurus, passing Alcyone (η Tau) – the brightest star in the Pleiades – on the 10^th, then Aldebaran (7.4°) on the 19^th.  With the rich starfield, choose your favorite stars and watch the planet pass them.  Use a binocular to attempt to spot the crescent moon with Mercury on the 20^th. The moon groups with Venus (5.6°) on the 23^rd.  It passes Elnath (β Tau) on the 30^th.

May

During May 3rd through May 5^th Venus reaches its maximum setting interval, 223 minutes after sundown. Mars is plotted on the chart beginning early during the month, setting less than five hours after sundown.  It passes Pollux (β Gem) on the 8th. Venus moves into Gemini, passing 1.7° from Messier 35 (M35) on the 9^th. The moon passes Venus on the 22^nd.  The next evening, Venus, Mars, Moon, and Pollux fit into a binocular’s field of view. Venus passes Castor (α Gem) on the 26^th and Pollux on the 29^th.

June

Venus reaches its greatest elongation (45.4°) on the 4^th. This is marked with GE on the Venus curve.  With this, Venus’ apparent pursuit of Mars begins to stall.  At the beginning of the month, Venus’ eastward motion is over 1° each night.  This is slowed to 0.6° per night at month’s end.  On the 13^th, Venus passes 0.8° from the Beehive star cluster. The moon passes 4.6° from Pollux on the 19^th. Two nights later, Venus, Mars, and the moon fit into a 6.3° circle. On the 22^nd, the moon makes a wide pass at Regulus (5.7°).  Five nights later, the moon passes 3.0° from Spica.  Venus only closes to 3.6° of Mars in a quasi-conjunction on the 30^th.  There is no Venus-Mars conjunction for this evening apparition of Venus.

July

Venus sets earlier each evening, losing over one minute each night. Early in the month, Venus sets at the end of evening twilight and sets during twilight during the remainder of its apparition. Saturn is appearing in the eastern evening sky when Venus is lower in the west. Venus is at the midpoint of its period of greatest brightness, marked by GB on the chart, on the 8^th.  Venus only closes the gap to Regulus at 3.5° on the 16^th, a quasi-conjunction. Mercury begins a poor evening appearance, reaching its greatest elongation next month.  With a binocular try for Mercury and the crescent moon on the 18^th.  Mercury, Moon, Venus, Regulus, and Leo span 19.5° on the 19^th.  They next evening, they span 18.5°, but the moon is east of the planets and Regulus. On the 22^nd Venus begins to retrograde, moving quickly toward inferior conjunction and an appearance in the morning sky.  The moon passes Spica on the 24^th. Jupiter rises less than four hours after sundown.

August

At the beginning of the month, Venus sets 17 minutes after sunset, quickly moving toward its inferior conjunction. The planet appears to be slipping into bright twilight, passing inferior conjunction between Earth and sun on the 13th.  Mercury reaches greatest elongation (27.4°) on the 10^th.  The separation is a favorable angle, but the ecliptic is poorly inclined with the western horizon. On the 18^th, use a binocular to look for Mars and the crescent moon, 1.1° apart. The Red Planet is immersed in bright evening twilight that continues through its solar conjunction during November. On the 24^th, the moon occults Antares during the evening. Saturn is at opposition with the sun on August 27^th.

September

Mars is the final bright planet in the western sky, but it is in bright evening twilight. Meanwhile, Saturn and Jupiter are in the eastern sky.  Use a binocular to spot the moon 1.9° from Mars on the 16^th. On the 20^th and 21^st, the moon is near Antares.

October

 The western sky is largely quiet.  Mars sets before Civil Twilight and it is lost in bright sunlight. The moon passes 5.0° from Antares on the 18^th. Mercury is at superior conjunction on the 20^th and begins its final evening apparition of the year.

November

Jupiter and Saturn are east of the meridian during the early evening.  Jupiter is at opposition and in the sky all night on the 2^nd. At midmonth, the moon moves through dimmer starfields near the ecliptic. Mars is at conjunction with the sun on the 18^th.

December

Mercury reaches its greatest elongation (21.3°) on the 4^th, setting 75 minutes after the sun and shortly after Nautical Twilight.  At 30 minutes after sunset, it is 6° up in the southwest.  On the 14^th, the crescent moon is 11.1° from Mercury.  At month’s end Saturn begins setting less than five hours after sundown.

The year’s evening sky promises considerable activity during the first three quarters of the year.  Venus passes planets, bright stars, and star clusters.  It approaches Mars and Regulus, but there are no conjunctions.  The moon makes pretty groupings with planets and stars during the year, occulting Antares on the August 24^th.  During the final quarter, Mars passes behind the sun and into the morning sky.  During December Mercury whips into the evening sky for a brief appearance with the moon.

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