2021, September 9: Rare Venus, Moon, Spica Spectacular

September 9, 2021:  After this evening’s grouping, Evening Star Venus, the crescent moon, and Spica do not appear this close together until 2026.  This is one of four groupings that fit into the same binocular field through 2036. For the fifth occasion during this evening apparition of Venus, the moon passes the brilliant Evening Star.

2021, September 9: Forty-five minutes after sunset, brilliant Venus, the crescent moon, and Spica are grouped together in the southwest.
Chart Caption – 2021, September 9: Forty-five minutes after sunset, brilliant Venus, the crescent moon, and Spica are grouped together in the southwest.

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by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:25 a.m. CDT; Sunset, 7:10 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

The crescent moon joins Venus and Spica in the western sky after sunset.  For the fifth time during this evening appearance of Venus, a crescent moon shines with the brilliant Evening star.  This evening Spica is part of the scene.  All three easily fit into the same binocular field of a standard 7 x 50 model with a 7° field of view.

Not until November 7, 2026, will Venus, the crescent moon, and Spica fit into the same binocular field. This is followed by a grouping during 2034 and 2036. 

Venus passes Spica at least once a year, sometimes more frequently as the planet dances from the morning sky to the evening sky.

The moon passes Venus and Spica each month, although spotting the trio together in a fairly compact grouping is a rare occurrence.

Here’s what to look for this evening:

Forty-five minutes after sunset, look toward the west-southwest, Venus is only about 8° above the horizon, shining through the colorful layers of evening twilight. The crescent moon is 3.9° to the upper right of Venus and 4.8° above Spica.

Just four evenings after the Venus – Spica conjunction, Venus is 5.0° to the upper left of Spica.  The planet is rapidly stepping eastward compared to the distant stars.

2021, September 9: Through a binocular, Venus, the moon, and Spica easily fit into the same field of view.
Chart Caption – 2021, September 9: Through a binocular, Venus, the moon, and Spica easily fit into the same field of view.

The trio nicely fits into the same field of a binocular.  You might notice that the night portion of the moon is gently illuminated by earthshine – sunlight reflected from Earth’s oceans, land, and clouds.

2020, July 17: The crescent moon appears near Venus before sunrise. The night portion of the moon is gently illuminated by earthshine.
Photo Caption – 2020, July 17: The crescent moon appears near Venus before sunrise. The night portion of the moon is gently illuminated by earthshine.

Earthshine can be photographed with a tripod-mounted camera.  Exposures can range to several seconds, depending on the camera’s settings.  On the photograph above, a Venus – Moon conjunction during 2020 shows a lunar crescent with nearly the same illumination as this evening’s grouping.  The separation was the same as this evening’s conjunction.  The camera’s settings for this photograph were: 5 seconds, f/5.6, 300mm lens, ISO 400.

The next grouping of Venus, the crescent moon, and Spica is December 9, 2023, although Venus is over 12° from Spica.  The moon and Venus are 3.7° apart.

During the early evening of September 14, 2026, the trio is in a lineup, nearly in a line, along the southwestern horizon, spanning over 15°.

2026, November 7: The closest grouping of Venus, the crescent moon, and Spica from 2021 through 2036.
Chart Caption – 2026, November 7: The closest grouping of Venus, the crescent moon, and Spica from 2021 through 2036.

Venus, the crescent moon, and Spica appear in a compact triangle on the morning of November 7, 2026, although this is not as symmetrical as this evening’s grouping.  The separations: Venus – Moon, 1.9°; Moon – Spica, 2.7°; and Venus – Spica, 1.3°.

Nearly two years later before sunrise, November 14, 2028, Venus, Spica, and the crescent moon are along a diagonal line, extending nearly 8°, but too far apart to fit into the same binocular field.

Expert sky watcher Robert C. Victor extended the search. Another grouping occurs in the morning of November 8, 2034. The largest gap is from the crescent moon to Spica, 6.7°. Mars is part of this gathering, 1.1° to the upper right of the lunar crescent. This is a snug fit into the same binocular field.

Victor named the 2026 grouping “the best” for this time span because of the proximity of the three objects.

On November 15, 2036, the crescent moon, Venus, and Spica are along a diagonal line that extends 6.7°, another snug fit.

Take a look at this evening’s gathering, four groupings of Venus, the crescent moon, and Spica from 2021 through 2036.

Detailed Daily Note:Twenty minutes after sunset, Mercury is over 4° up in the west-southwest.  Use a binocular to see it.  The speedy planet is on route to its evening greatest elongation, but the appearance is the worst evening apparition of the year.  At this hour you might spot the crescent moon (3.0d, 11%), 13.0° to the upper left of Mercury with Venus below it.  By 45 minutes after sunset, the moon is about 10° up in the west-southwest, 3.9° to the upper right of Venus and 4.8° above Spica.  The Venus – Spica gap has grown to 5.0° this evening.  With the binocular notice the earthshine on the night portion of the moon.  The crescent moon, Venus, and Spica fit nicely into a binocular’s field of view.  Saturn (m = 0.4) and Jupiter are farther eastward.  At this hour Saturn is over 20° up in the southeast, 16.9° to the upper right of Jupiter.  The Jovian Giant is about 16° above the horizon.  At two hours after sunset, when the planets are higher, both are about the same altitude.  Saturn is over 27° up in the south-southeast, while Jupiter is nearly 26° above the southeast horizon.  Use a binocular to find Saturn 1.0° to the lower right of υ Cap and Jupiter, 4.4° to the upper right of ι Aqr, 1.4° to the lower right of μ Cap, and 1.6° to the upper left of Deneb Algedi.  Both planets continue to retrograde in front of the starry background of Capricornus.

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