JAMESTOWN, N.D. (NewsDakota.com) – The naked-eye planets are “morning stars” this month, rising only a few hours before dawn (except for Venus, which is behind the Sun).
However, those who are willing to rise early will witness a close planetary conjunction, and the first total lunar eclipse visible in North America since September 27, 2015, takes place on the very last day of this month.
Jan. 1 (New Year’s Day, Mon.): The Moon will reach perigee, its closest distance to the Earth during the former’s current orbital period, at 3:49 p.m. CST, when it will be 221,559 miles away. As Full Moon occurs less than five hours later at 8:24 p.m., this qualifies it as another “Super Moon,” although it is only 8% larger than usual. At that moment Luna will be 33½ minutes of arc across, 32¾ degrees above the eastern horizon, and 221,582 miles distant.
Jan. 3 (Wed.): Around midnight the Earth will attain perihelion, its closest approach to the Sun this year, when the two bodies will be 91,401,983 miles apart. If we are at our closest to the star, why are we so cold? In January the Earth’s axis tilts 23.4 degrees away from the Sun, so that the star’s rays fall on the northern hemisphere indirectly. At local solar noon (actually 12:38 p.m., when the Sun has climbed highest over the southern horizon), the star will be elevated just 20 1/3 degrees, and there will be only 8 hours and 38 minutes of daylight. The tilt of the Earth’s axis has far more to do with the warmth reaching the Earth than our planet’s slightly varying distance from the Sun.
The Quadrantid meteor shower should reach its peak of 110 meteors per hour this evening, but the glare from the waning gibbous Moon will wash out most of them. Count yourself lucky this year if you manage to see twenty of the brightest Quadrantids per hour. These objects were named after the obsolete constellation of “Quadrans Muralis,” the mural quadrant, from which they appeared to originate. At 6 a.m. Thursday the shower’s radiant (apparent point of origin) will be nearly 60 degrees above the ENE horizon, between the lozenge-shaped head of Draco the Dragon and the end of the handle of the “Big Dipper.” The parent body of the Quadrantids, one of the many comets found by amateur astronomer Don Machholz, was not identified until 1986; the shower is probably less than 500 years old.
Jan. 5 (Fri.): Around 2 a.m. this morning, the Moon will pass only 0.9 degree north of blue-white Regulus (magnitude 1.35), the brightest star within the constellation of Leo the Lion. Regulus, which lies 77½ light-years from us, marks the bottom of the “Sickle” or reversed “Question Mark” asterism within Leo. At this hour the Moon will be 0.55 degree in apparent diameter, 228,238 miles distant, and 85.44% illuminated.
Jan. 7 (Sun.): As I mentioned in last month’s column, many astronomers think that the “Star of Bethlehem” might have been a conjunction (close encounter) between two or more bright planets. A good example of this occurs this morning, when bright beige Jupiter passes only 0.3 degree north of orange-red Mars. When astronomical twilight begins at 6:30 a.m., Jupiter (mag. –1.8) will be 21 5/12 degrees above the SE-SSE skyline, with fainter Mars (mag. 1.5) beneath it. If you own a telescope and use low magnifications, you should be able to fit both worlds within the same field of view; binoculars or field glasses are just powerful enough to show Jupiter as a tiny disk. Jupiter appears 21 times brighter than Mars even though the former body lies much farther away from Earth; the gas giant presents more surface area than relatively puny Mars, and its clouds reflect more light toward us than the rocky Martian surface. At this time Jupiter will be 33.6 arc-seconds in apparent span, 99.39% illumined, 545,594,815 miles from Earth, and 504,861,580 miles from the Sun; Mars will be only 4.9 arc-seconds across, 92.77% lit, 176,430,122 miles from Earth, and 151,118,255 miles from the Sun. However, the Earth is catching up gradually with the “Red Planet,” which will brighten by 0.3 magnitude by the end of the month.
Jan. 8 (Mon.): Last Quarter Moon occurs at 5:25 p.m., when it will be 30.36 arc-minutes across, 242,070 miles away, and 44 degrees beneath Jamestown’s NNW horizon.
Jan. 11 (Thur.): The waning crescent Moon joins Jupiter and Mars before dawn. At 4 a.m. Luna will be 5.55 degrees above the ESE horizon, 29.88 arc-minutes in apparent diameter, 26½% sunlit, and 246,940 miles distant. 3.95 degrees to its lower right will be bright cream-colored Jupiter (mag. –1.9), then 34 arc-seconds across, 99.35% lit, 504,805,807 miles from the Sun, and 540,426,472 miles from Earth. 3 degrees below Jupiter and 3.85 degrees to the Moon’s lower right will be ruddy Mars (mag. 1.39); the “Red Planet” will be then 5 arc-seconds in span, 92.48% illumined, 150,802,206 miles from the Sun, and 173,167,373 miles from the Earth. Since all three heavenly bodies are so close to the skyline, they might be hard to see (use the Moon as your initial guide); they will rise higher as dawn approaches, but will have moved farther apart by then. Still, they will form a nice triangle in the predawn sky.
Jan. 15 (Mon.): Just as the January 1st Moon was the closest “Super Moon” of the year, 2018’s most remote lunar apogee (farthest distance from the Earth) occurs today, two weeks later. At 8:10 p.m., the Moon will be 252,565 miles away, a slim crescent merely 0.96% illuminated, 29 5/12 arc-minutes across, and 37¾ degrees beneath Jamestown’s WNW horizon.
Jan. 16 (Tue.): New Moon occurs at 8:17 p.m., when it will be 29½ arc-minutes in apparent diameter, 251,720 miles away, and 30.54 degrees below the western horizon.
Jan. 24 (Wed.): First Quarter Moon takes place at 4:20 p.m., when it will be 31 7/12 arc-minutes in apparent span, 235,134 miles distant, and 41 degrees above the SE horizon.
Jan. 30 (Tue.): The second lunar perigee this month happens at 3:57 a.m., when it will be 223,068 miles away, 33.28 arc-minutes across, 98.03% illumined, and 31.4 degrees above the western horizon. It nearly coincides with the second Full Moon of the month, making it another “Super Moon” (although not as spectacular as the one on New Year’s Day).
Jan. 31 (Wed.): The month concludes with a bang as a total lunar eclipse takes place this morning. Below is the chronology of this event for Jamestown:
– 4:50 a.m.: The eastern rim of the Moon, which will be then 99.98% sunlit and 30.6 degrees above the WSW-W skyline, makes contact with the penumbra (the Earth’s fainter outer shadow). The penumbra is so faint that it will not become noticeable for a half-hour or so, when the eastern part of the Moon might display a darker grayish tint. Wearing sunglasses (of all things!) often heightens the contrast between the penumbra and the rest of the Moon. Meteorologist and astronomer Joe Rao also recommends projecting the lunar image through a telescope eyepiece on to a sheet of paper; this too increases the contrast, and has enabled him to detect the penumbra within 33 minutes after the start of lunar eclipses.
– 5:48 a.m.: The partial stage of the eclipse begins when the Moon’s eastern rim makes contact with the Earth’s umbra, or darker inner shadow. At this time Luna will be almost 21 degrees over the western horizon and 99.99% lit.
– 6:51 a.m.: Total eclipse begins as the Moon, now 16 1/3 degrees above the W-WNW skyline, moves fully into the Earth’s umbra. Because some sunlight is refracted through the Earth’s atmosphere and reaches the lunar surface, the Moon is not darkened completely; it probably will be colored orange. The “wild card” this year might be the smoke from the California forest fires; if enough soot is thrown into the atmosphere, the light reaching the Moon will be reduced, so that it appears reddish, brick-red, or grey. I saw a total lunar eclipse near Cleveland, Ohio, in 1963 where the Indonesian volcano Mt. Pinatubo had thrown so much ash into the sky that the Moon disappeared entirely at mid-eclipse; except for a circular gap in the star field, nobody would have realized that the Moon was there! What will pan out during this month’s eclipse?
– 7:27 a.m.: Full Moon occurs technically with the Moon directly opposite the Sun (which from a lunar perspective would be a total eclipse of the Sun, with the darkened Earth surrounded by a halo of fiery light). At this moment the Moon will be just less than 5 degrees over the WNW horizon, 33.228 arc-minutes across, and 223,816 miles away.
– 8:04 a.m.: The Moon sets on Jamestown’s WNW horizon, mere minutes before its eastern limb exits from the Earth’s umbra.
– 8:08 a.m.: The Moon begins moving out of the umbra, returning to a partial eclipse stage.
– 9:12 a.m.: The Moon departs entirely from the Earth’s umbra, returning to the penumbral eclipse stage.
– 10:10 a.m.: The eclipse ends entirely as the Moon exits the Earth’s penumbra.
On July 27 there will be another lunar eclipse, but it will be visible primarily from central Africa and central Asia.
Celebrate the New Year with this spectacular heavenly event (and pray that the weather will cooperate!).
This article was written by Dr. Timothy Bratton, Professor Emeritus of History at the University of Jamestown and Amateur Astronomer.
