2022, December 27: Crescent Moon, Rare Five-Planet Exhibition


December 27, 2022:  The crescent moon appears with the five bright planets – Venus, Mercury, Saturn, Jupiter, and Mars – after sundown.

Photo Caption – 2022, July 30: The crescent moon with earthshine. (Photo by MJB)


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 7:17 a.m. CST; Sunset, 4:26 p.m. CST.  Check local sources for sunrise and sunset times for your location.

Daylight is slowly growing longer, although slowly.  Latest sunrise time (7:18 a.m. CST) begins on the 28th and lasts through January 10th.

Jupiter’s Great Red Spot’s transit times, when it is in the center of the planet in the southern hemisphere: 1:09 UT, 11:04 UT, 21:00 UT. Convert the time to your time zone. In the US, subtract five hours for EST, six hours for CST, and so on.  Use a telescope to see the spot.  Times are from Sky & Telescope magazine.

Here is today’s planet forecast:

Morning Sky

Chart Caption – Late December mornings: 2022: Arcturus, Boötes, Corona Borealis, and Gemma are in the east-southeast before sunrise.

With the bright planets in the evening sky, several bright stars are visible before sunrise.  Step outside an hour before sunup and look high in the southeastern sky.  Topaz Arcturus, the brightest star in the northern half of the sky, is there; that is, the brightest star north of the celestial equator, the imaginary celestial circle above Earth’s equator.

The star’s name means “bear guard.”  Along with its constellation, Boötes, Arcturus seems to chase the Big Bear, its brightest stars marked by the seven stars of the Big Dipper, westward.

The star is relatively nearby, 37 light years, and shines with a brightness of about 100 suns. If placed at the distance of Sirius, 8.6 light years, Arcturus would easily outshine the Dog Star and rival the brightness of Jupiter.

The 1933 World’s Fair used Arcturus’ light to energize photoelectric cells attached at the eyepieces of four telescopes in the eastern U.S. – Yerkes Observatory, University of Illinois, Allegheny Observatory, and Harvard Observatory – to switch on a searchlight that signaled the beginning of the fair.

Arcturus was thought to be 40 light years away.  The 1933 fair was 40 years after the 1893 Columbian Exposition

There is a competing story about how the searchlight was signaled from the light of a telescope set up on the fairgrounds.

Boötes resembles a kite or a sugar cone with a scoop of ice cream on top.  Some modern story tellers spin a yarn that Corona Borealis – the Northern Crown – is a second scoop that has topple from the sugary treat.

The Crown’s brightest star is Alphecaa – meaning “the broken or fractured one.”  Sometimes the star is called Gemma. The crown’s stars are not bright and a binocular may be needed to see them, especially from urban or suburban locales.

Arcturus makes its first evening appearance after sunset during early spring and by early summer it is in this place again.

Evening Sky

Chart Caption – 2022, December 27: Venus and Mercury through a binocular, 30 minutes after sundown.

The five-planet display continues during evening twilight.  At thirty minutes after sundown, begin looking for Venus and Mercury in the southwest.  Even though twilight is bright in the western sky, Venus is bright enough to be seen without a binocular’s optical assist, although initial identification of the Evening Star with the binocular guides the view to Mercury.

Look for Venus to the right of the southwest direction and over 5° above the horizon.

The Mercury is 2.1° above Venus.  Place Venus at the center of the field of view. Mercury is above it.

Chart Caption – 2022, December 27: At 45 minutes after sundown, Venus, Mercury, Saturn, the crescent moon, and Jupiter are visible from south to the southwest.

As the sky darkens further, Mercury becomes visible without the binocular, but the planets are lower in the sky.

During this time, look for the crescent moon, 27% illuminated, less than halfway up in the sky in the south-southwest.  The crescent is over 20° to the lower left of bright Jupiter, about halfway up in the south.

By 45 minutes after sunset, Venus and Mercury are lower in the southwest.  Saturn, over 15° to the lower right of the moon, is about one-third of the way from the crescent to Venus.  The Ringed Wonder is the dimmest of the bright five planets, slightly dimmer than Mercury.

Mercury is quickly fading in brightness and tomorrow may be the last evening to see it at this hour without a binocular.

Chart Caption – 2022, December 27: Mars is in the eastern sky during early evening. Aldebaran and Capella are nearby.

Farther eastward, Mars is about one-third of the way up in the east.  Aldebaran, the brightest star in Taurus, and Capella, brightest in Auriga, are in Mars’ vicinity, but they are not as bright as the Red Planet.

We are nearing the final time to see five planets simultaneously until October 2028.  After Mercury leaves the scene, the bright four planets are visible simultaneously until early February.  Venus passes Saturn on January 22nd and Jupiter on March 1st. Venus does not pass Mars during this evening appearance.



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