December Astronomy: The month heralds the onset of winter and an evening planetary extravaganza!  - Coachella Valley Independent

December Astronomy: The month heralds the onset of winter and an evening planetary extravaganza! – Coachella Valley Independent

All of the planets in our solar system (except Earth, our viewing platform) appear in a long line in the early December evening sky.

Mercury and Venus start the month deep in the brilliance of the sun; emerging on the other side of the sun, they will become visible around the middle of the month from sites with a good view towards the direction of the setting sun, but 30 minutes later. Venus will be able to be seen with the naked eye, and Mercury with binoculars in the same field, because the sky darkens a little.

Watch the moon approach each of the other three planets with the naked eye over the span of 10 days: Saturn in Capricorn on November 28, Jupiter in Pisces on December 1, and March in Taurus on December 7th. In a rare occultation of the red planet at opposition and at its brightest (magnitude -1.9), the full moon will cover and uncover Mars early in the evening.

Uranus and Neptune, discovered in 1781 and 1846 respectively, are weaker and require at least binoculars and a search map. It will be best to search for them when the moon is absent, or just a crescent and not nearby.

The moon returns to the evening sky to sweep all seven planets over 11 nights, from December 24 to January 24. 3.

December 2022 sky calendar, The December Evening Sky Constellation Map and Uranus Search Chart will help you see the events mentioned in this column and find your way through the sky.

Observers equipped with good quality telescopes can admire Jupiter, its equatorial cloud belts and four satellites discovered by Galileo, as well as the rings of Saturn. Using medium and higher magnifications, also try a surface feature on Mars discovered in 1659: Mayor of Syrtis a dark triangular patch of volcanic rock. It passes just north of the center of the Mars disk on December 1 at 8:48 p.m. One rotation of Mars on its axis takes just over 24 hours, so look for the same characteristic 36 minutes later each evening – December. 2 at 9:24 p.m.; December 3 at 10 p.m., etc. to December 6 at 11:48 p.m. Continuing, it passes the center of the Martian disk 36 minutes later the following night, and so on, ending on December 14 at 4 a.m. When our local atmosphere is stable (good vision), and when Mars is not low in our sky, Syrtis Major can be seen up to two hours before or after these ideal times. Additionally, if you notice a bright northern edge on Mars’ disk, you may be seeing the North Polar Hood (NPH), a cloudy bridge over the area above Mars’ north pole. The northern vernal equinox of March will occur on December 26. In the following weeks, the NPH is expected to dissipate, exposing the northern polar cap of frozen carbon dioxide and frozen water.

At twilight on December 7, the full moon is close in the upper right of low Mars in the east-northeast, and ready to occult it. Thirty minutes after sunset, Mars appears about one degree lower left of the moon’s center, or three-quarters of a degree from its edge. From the Coachella Valley around 6:30 p.m., the moon takes about 30 seconds to “choke” Mars, because the planet is not a point source, but has a sensitive disk, at least when viewed with a telescope. Around 7:30 p.m., Mars reappears on the upper edge of the Moon.

Using binoculars within 30 minutes after sunset on December 8, try Mercury at 4.8° upper left of Venus, very low southwest to west-southwest, with the moon rising within 12° lower left of Mars in the east-northeast. From a location with unobstructed views in critical directions – no tall mountains – you may be able to spot the six bright members of the lineup, in order from horizon to horizon, Venus, Mercury, Saturn, Jupiter, Mars and the moon, simultaneously. That’s a range of 177°! After December 8, the moon rises later and falls from the early evening sky for two weeks, while Mercury and Venus become easier to see as both rise higher at night.

Those who like to go out early can follow the moon in the morning sky. It is almost full, in the west-northwest, in the lower right of Mars on December 7 and in the upper left on December 8; waning gibbous, near the “twin” stars of Gemini, Pollux and Beaver, December 10 and 11; near Regulus, heart of Lion, on December 14; like a crescent near Spica, December 18; and finally, as a thin, old 5% crescent low in the southeast with Antaresheart of Scorpius, 5-6° lower left, December 21.

Returning our attention to the evening sky, we find Mercury appearing farthest (5.9°) to the upper left of Venus on December 16 and 17; reaching the greatest elongation of 20° from the sun and 5.3° upper left from Venus on December 21; and rising highest at dusk on December 23 and 24.

On December 19, Saturn is halfway between Venus and Jupiter, 39° from each.

On December 21 at 1:48 p.m., the Sun, in the constellation Sagittarius, the Archer, enters the zodiac sign of Capricorn and reaches its southernmost excursion directly above the Tropic of Capricorn in the South Pacific Ocean. . This marks the start of winter for the northern hemisphere. That evening, Jupiter is 90° east of the sun, and only 1.3° south of the place in the constellation of Pisces (called the “first point of Aries”), where the sun will appear. In early spring.

As night fell the same evening, a line from Jupiter 3.7° west-southwest (lower right) to the 5.5 magnitude star 20 Piscium, extending its own length in straight line beyond the star, locates Neptune of magnitude 7.9, 7.4° west-southwest of Jupiter. The star 20 Psc marks the end of the handful of an asterism we call Neptune’s Dipper, composed of six stars of magnitude 4.4 to 5.9, all now within 1.7 to 4.7° west-southwest to south-southwest (bottom right, bottom and bottom right left) of Jupiter. Neptune’s Dipper is easy for almost any binocular; for a weaker Neptune, we recommend an aperture of at least 50mm in dark skies.

Uranus at magnitude 5.7 is a much easier target. On our additional Sky calendar content page, we describe how to get Taurus Head (Aldebaran and the Hyades cluster) at the head of Cetus, the sea monster, depicted on our constellation map. Next, we trace a star jump from Mu in the head of Cetus to the isosceles triangle of Omicron, Sigma and Pi in Aries, shown on our search map for Uranus. On December 22, Uranus, in retrograde, crosses the line from Pi to Sigma: 1.5° from Pi and 0.9° from Sigma, entering the triangle, where it will remain for two months until it emerges on the same side on 21 February.

On December 24, the moon returns to the evening sky as a crescent, in a nice gathering with Mercury and Venus. On this day, note the position of the sun from southwest to west-southwest, 38 minutes before sunset. On December 24, Venus follows the path of the sun, 68 minutes later. You can also find Venus at 8° to the bottom right of the 4% crescent moon. The binoculars will show Mercury 5° to the right of the moon and 4° to the upper left of Venus.

At dusk on December 25, the 10% crescent will be in the southwest, with Venus at 21° lower right; Mercury 3.5° upper left of Venus; and Saturn 12° upper left of the moon.

On December 26, the 19% crescent will appear within 6° to the left of Saturn. The moon is halfway between Venus and Jupiter, 35° apart. Mercury is 2.8° upper left of Venus.

On December 27 at dusk, the 29% crescent moon will be high in the south-southwest, with Saturn and Venus at 19° and 48° respectively in the lower right and Jupiter at 21° in the upper left of the moon. . Mercury will be only 2° above Venus. Mars will be in the eastern sky, 90° east of the moon.

Mercury passes within 1.5° north (upper right) of Venus on December 28 and will sharply fade and drop lower at dusk in the final days of the month. The Moon tonight is a large crescent, 39% full and 7° lower right of Jupiter. Watch Saturn crawl its 30-year circuit around the zodiac: tonight Saturn passes 1.3° north of the 3.7 magnitude star Gamma in Capricorn, and will pass 1.4° north of Delta Cape of magnitude 2.9, at the end of the Sea Goat’s tail, on January 14. Before that, Saturn will form an isosceles triangle with the two stars, 1.6° apart, on January 6.

At dusk on December 29, the moon is in its first quarter phase, half full, and is located 90 degrees or a quarter circle east of the sun. Jupiter is 7-8° west, or right, of the moon at dusk. Mercury is 1.7° to the right of Venus and slightly higher. On December 29 and 30, the moon and seven planets – in the order of their positions in the sky from west to east, Mercury, Venus, Saturn, Neptune, Jupiter, the moon, Uranus and Mars – reach their minimum duration during of this appearance. , 135°.

On December 30, the gibbous moon, 61% full, is 21° upper left of Jupiter. Mercury, rapidly fading as it faces more of its dark side toward us, lies less than 2.9° lower right of Venus.

By New Year’s Eve twilight, the 71% moon has nearly reached halfway through the 68° gap between Jupiter and Mars. Say goodbye to Mercury, 4.4° lower right of Venus. Sirius, the “Dog Star”, peaks in the south in the middle of the night, halfway between sunset on New Year’s Eve and sunrise on New Year’s Day. Check out Robert Frost’s short poem, “Canis Major,” for a delightful description of the dog’s trek from east to west across the southern night sky.

The moon completes its sweep past all planets, appearing 9° upper right of Mars at dusk on January 2, and less than 4° lower left of the Red Planet on January 3. The full moon will occur on Jan. 6, just 6° from the “twin” stars Pollux and Castor at dusk.

Venus will become a prominent evening “star” in early 2023, providing wonderful pairings with stars and other planets, and a farewell display of crescent phases in June-July, all to be covered in Sky calendar. For $12 a year, subscribers receive quarterly mailings, each with three monthly issues. For more information and a sample, visit

Robert Victor is at the origin of the monthly Abrams Planetarium Sky Calendar in October 1968, and still produces occasional issues, including the December 2022 edition. He enjoys being outdoors and sharing the wonders of the night sky. Robert Miller, who provided the twilight maps and Uranus search map accompanying this column, did graduate work in planetarium science and later astronomy and computer science at Michigan State University, and remains active in research and public education in astronomy.

#December #Astronomy #month #heralds #onset #winter #evening #planetary #extravaganza #Coachella #Valley #Independent

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