2022, December 10:  Gemini Moon, Overnight Planets


December 10, 2022: The moon is with the Gemini Twins during the night.  Mars, Jupiter, and Saturn continue their overnight display, making the plane of the solar system.

Photo Caption – Scientist-astronaut Harrison H. “Jack” Schmitt, lunar module pilot, took this photograph of his two fellow crew men aboard the Apollo 17 spacecraft during the final lunar landing mission in NASA’s Apollo program. That is astronaut Eugene A. Cernan, commander, who is seemingly “right side up.” Astronaut Ronald E. Evans, command module pilot, appears to be “upside down.” (NASA Photo)


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 7:07 a.m. CST; Sunset, 4:20 p.m. CST.  Check local sources for sunrise and sunset times for your location.

Today’s sunset time is the earliest of the year.  This continues through the 14th.

Jupiter’s Great Red Spot’s transit times, when it is in the center of the planet in the southern hemisphere: 2:01 UT, 11:57 UT, 21:53 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.  December 10, 1972, was the mission’s fourth calendar day. On this day, the command module/lunar module combination entered the moon’s orbit.  Maneuvers were made to adjust the spacecraft’s orbit for the lunar landing.

Summaries of Current Sky Events

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2022, December 10: Before sunrise, the bright moon is in the western sky below the Gemini Twins and to the upper left of Mars.

This morning, an hour before sunrise, the gibbous moon, 85% illuminated, is about one-third of the way up in the western sky.  It is nearly 10° below Castor, one of the Gemini Twins.  Pollux is 4.5° to the left of its twin.

Bright Mars, a few days after its solar opposition, is low in the west-northwest.  It is less than 10° above the horizon.  Better views occur during the early evening hours when it is higher in the eastern sky.

Evening Sky

Chart Caption – 2022, December 10: Venus and Mercury are visible during bright evening twilight.

Venus and Mercury are becoming easier to see, although they are in bright evening twilight.  Seeing them is challenging but improving.  More southerly sky watchers can see the planets higher, a little later, and in a slightly darker sky.

At twenty minutes after sundown, brilliant Venus is nearly 4° up in the southwest.  It is visible through a binocular.  Mercury is in the same binocular field of view, 5.2° to the upper left of the Evening Star.  Hold the binocular so that Venus is in the lower right portion of the field of view.  Mercury is to the upper left.

Find a clear horizon looking to the southwest.  Looking from a hilltop or elevated structure is helpful.  Venus is to the north along the horizon or to the right of the southwest point.  A compass helps find the precise directions in this bright twilight to assist with finding the planets.

At this early time, the five bright planets are in the sky, but difficult to locate in this bright early twilight, especially Saturn, the dimmest of the bunch. In about two weeks all five planets are visible simultaneously in a darker sky.

Chart Caption – 2022, December 10: Jupiter and Saturn are in the southern sky after sundown.

By an hour after sundown, Venus and Mercury are below the horizon.  At that time bright Jupiter is about halfway up in the sky above the south-southeast horizon.  It is moving eastward in front of a dim Pisces starfield.

Chart Caption – 2022, December 10: Jupiter and Neptune tightly fit into the same binocular field of view.

Look early this evening, before the moon rises about two hours after sundown, to see Jupiter and Neptune in the same binocular field of view.  They fit tightly in the field. 

Neptune is a dim, bluish star to the west (right) of Jupiter.  Put Jupiter near the left side of the view to see Neptune on the right side. See your last views of Jupiter and Neptune together until 2035 before Jupiter moves out of the binocular’s field of view.

This evening, two of Jupiter’s large moons – Ganymede and Callisto – are visible through the binocular.  They appear as dimmer stars near the planet – Ganymede, to the west of Jupiter, and Callisto, east of the planet. Perhaps Europa is visible between Callisto and the planet.

Chart Caption – 2022, December 10: Through a binocular, Saturn is with stars in eastern Capricornus, Deneb Algedi, Nashira, and Iota Capricorni (ι Cap).

Saturn is farther westward, moving eastward in front of stars in eastern Capricornus.  Through the binocular, the Ringed Wonder is 2.0° to the upper right of Nashira and 2.6° to the upper left of Iota Capricorni (ι Cap on the chart).

Notice the star Fomalhaut, meaning “the mouth of the southern fish,” and Deneb Kaitos, “the tail of the sea monster,” below this planet pair.

Chart Caption – 2022, December 10: Mars is with Taurus during the night.

At this hour, Mars is about 15° above the east-northeast horizon.  It continues its retrograde in front of Taurus.  The line of sight from Earth to the planet continues to move westward as Earth moves away from the slower-moving Red Planet.

Mars is 8.4° to the upper right of Elnath, the constellation’s northern horn, and 9.3° to the upper left of Aldebaran, the pattern’s brightest star.  With the moon still below the horizon, look for the Pleiades star cluster, above Mars and the main stars of Taurus.

Chart Caption – 2022, December 10: The moon is near Pollux.

About two hours after sundown, the moon peeks above the east-northeast horizon.  The three bright planets are along an arc of the ecliptic, the plane of the solar system.  Bright Jupiter is halfway up in the south, while Mars is about one-third of the way up in the east, and Saturn is over 20° up in the southwest.

Three hours after sundown, the gibbous moon, 82% illuminated, is nearly 10° up in the east, 3.2° to the right of Pollux.

By tomorrow morning, Mars is low in the west-northwest. The moon is still near the Gemini Twins.



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