December 16, 2022: The morning moon is in front of Virgo near the star Zavijava. The bright outer planets – Mars, Jupiter, and Saturn, are on display during the early evening.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 7:12 a.m. CST; Sunset, 4:21 p.m. CST. Check local sources for sunrise and sunset times for your location.
Jupiter’s Great Red Spot’s transit times, when it is in the center of the planet in the southern hemisphere: 6:58 UT, 16:54 UT; Dec. 17, 2:50 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.
This is the 50th anniversary of the last Apollo lunar mission – Apollo 17. On December 16, 1972, the service module’s rocket fired to achieve the speed needed to leave lunar orbit and return Eugene Cernan, Harrison Schmitt, and Ronald Evans toward Earth.
Summaries of Current Sky Events
Here is today’s planet forecast:
The moon is at the Last Quarter (waning half) phase at 2:56 a.m. CST.
At one hour before sunrise, the lunar orb, 49% illuminated, is over 50° up in the south. It is 2.8° to the upper left of Zavijava – meaning “the corner of the barking dog” – and 10.0° below Denebola – the tail of Leo.
Zavijava is also known as Beta Virginis, initially rated as the second brightest star in Virgo. The constellation has at least three stars, Porrima, Auva, and Vindemiatrix, that are brighter than Zavijava.
A five-planet display is beginning to form in the western sky after sundown. Venus and Mercury are still a challenging view during bright twilight.
At twenty-five minutes after sundown, Mercury is less than 10° above the southwest horizon. A binocular is needed to see it. Brilliant Venus, less than 5° above the horizon, is 5.9° to the lower right of Mercury and in the same binocular field of view. The sky is still bright, so be patient in finding them.
Sky watchers farther southward can see these planets higher in the sky and a little later into twilight.
An hour after sunset, Mercury and Venus are very close to the horizon or below it. The three bright outer planets are along the arc of the ecliptic from east-northeast to south-southwest.
Red-orange Mars is over 20° above the east-northeast horizon, 8.5° to the upper left of Aldebaran, the brightest star in Taurus. The Red Planet continues the illusion of retrograde through January 12.
Retrograde occurs with any celestial object – planet, asteroid, comet – that revolves around the sun farther away than Earth. In the orbits, the planets revolve in a counter-clockwise direction when viewed from north of the solar system. From our world, we generally view the planets moving eastward compared to the starry background. When faster moving Earth passes between the sun and the planet, the distant world seems to stop moving eastward and move westward. The line of sight from Earth to the planet and on to the stars begins to move westward. Then after a time, the eastward course of the planet returns after Earth has moved well past the outer planet.
The inner planets – Mercury and Venus – retrograde as well. This occurs when they pass our planet as they move from the evening sky to the morning sky.
Farther westward along the ecliptic – the plane of the solar system – Jupiter is “that bright star” in the south-southeast at this hour. It is moving eastward against a dim Pisces’ starfield.
Saturn is about 40° to the lower right of Jupiter and about one-third of the way up in the sky in the south-southwest. The planet is dimmer than Jupiter and Mars, but brighter than most of the other stars in the sky tonight.
The Ringed Wonder is moving eastward against the stars in eastern Capricornus. Use a binocular to notice its motion compared to Nashira. Saturn passes the star on the 27th and 28th. This evening the gap from Saturn to Nashira is 1.7°.
During the next 90 minutes or so is the best time to see these three planets simultaneously before Saturn gets too low in the southwest to be found easily.
At 8:50 p.m. CST, Jupiter’s Red Spot is in prime viewing location through a telescope at the center of the planet in the southern hemisphere. At this time in Chicago, Jupiter is about one-third of the way up in the southwestern sky. Star gazers in the western US see the planet higher in the sky.
When admiring the Red Spot, look toward the eastern sky. The great congregation of stars that are prominent during the middle of winter are in the eastern sky – Sirius, Betelgeuse, Rigel, Aldebaran, Capella, Castor, Pollux, and Procyon. And this year, Mars joins them.
December 31, 2022: Mercury begins to depart the evening sky, leaving four bright planets – Venus, Saturn, Jupiter, and Mars on display for New Year’s Eve.Keep reading
December 30, 2022: The night’s brightest star, Sirius, is in the south at midnight as the year ends. The bright planet evening display continues as Mercury disappears into bright twilight.Keep reading
December 29, 2022: The evening planet display is ending as Mercury begins to retrograde and fade in brightness. Look for Venus, Mercury, Jupiter, Moon, and Mars after sundown.Keep reading