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January 2018 Skies

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January Skies

by Dick Cookman


Highlights: Comet Journal, Martian Landers, Meteor Showers, Planet Plotting, January Moon

Focus Constellations: Gemini, Orion, Taurus, Auriga, Perseus, Cassiopeia, Cepheus, Draco, Ursa Minor, Ursa Major, Camelopardalis, Lynx

Comet Journal

C/2017 T1 (Heinze) crosses the Milky Way in January as it moves through Lynx, Camelopardalis, Cassiopeia, Andromeda, and into Pegasus. Its orbit opens to the South and it rose through the plane of our orbit between Earth and Mars in Cancer on Christmas. After crossing closest to Earth when it approaches Declination 70°N on Jan. 5th, it will be closest to the Sun (perihelion) on Feb. 21st. The comet will then drop southward and fall through the plane of Earth’s orbit in early April. It will be about 4 million miles outside of our orbit, near where Earth will be on July 4th. It may reach 9th magnitude when closest to Earth and will drop to 11th or 12th magnitude when closest to the Sun. No other comet is expected to reach 10th magnitude this month.

Mars Landers

Opportunity is descending eastward down "Perseverance Valley” which cuts through the western rim and leads to the floor of "Endeavor Crater", the 14 mile wide crater located on "Meridiani Planum". The crater was formed by impact during the ”Noachian“ age on Mars, over 3.7 billion years ago. The valley is thought to have been carved by ancient water or debris flows and the rover recently observed evidence that the most significant erosion currently in action is due to westward winds blowing up the valley from the crater floor. Larger rocks in the valley display sediment piled up in wind shadows on their westward sides and sediment is absent on the North, East, and South sides. "Perseverance Valley” cuts through ”Noachian“ impact debris making up the rim of the crater but does not continue through younger layers on its floor which appear to be 3.7 billion years old. Therefore, the valley may be older as it may be buried by those layers.

As Opportunity continued its descent, it survived temperatures below -140°F during the solstice interval which culminated on November 20. The rover is continuing its program of panoramic imaging of “Perseverance Valley” because scientists hope this examination may help determine the nature of the fluids which carved the valley. Solar array energy production averaged 390 watt-hours per sol and as of Sol 4942 (Dec. 18, 2017) Opportunity achieved a total distance traveled on Mars of 28.01 miles (45.08 kilometers ).

Following the successful delivery of the 18 month old sand sample and favorable testing of the drill on the ground on Sol 1863 (November, 1, 2017) Curiosity resumed its climb of 18,000 foot high “Mt. Sharp” in 96 mile wide “Gale Crater”. On Sol 1875-1876 (11/15/17), Curiosity approached a boundary exposed in the middle and upper part of Vera Rubin Ridge between a lighter colored lower rock layer and a darker upper layer which was observed from orbit. Rocks exposed vary in color due to differences in chemical content which can be attributed to processes associated with original deposition and post deposition alteration. Structures were observed and the Alpha Particle X-Ray Spectrometer was utilized to determine chemical makeup. Clues in chemical composition and sedimentary structures may provide information about the origin of this prominent feature.

Meteor Showers

One of the best meteor showers of the year will be overwhelmed by glare from the Moon. The Quadrantid Meteor Shower peaks on the morning of the 4th, and typically approaches as many as 100 meteors per hour including numerous fireballs in dark skies with minimal light pollution. Glare from the waning gibbous moon will wipe out the western sky and dim the meteors shooting out of northern Bootes which will be east of the zenith during the best viewing before dawn. The Delta Cancrids on the 17th which peak after New Moon avoid lunar glare but are a minor shower averaging 4 meteors per hour emanating out of Cancer in dark western skies before dawn.

Planet Plotting

Venus (-3.8) in Sagittarius might be visible in the glow of sunrise in early January but will rapidly be lost as Superior Conjunction occurs on the 9th. Mercury (-0.2 to -0.5) in Ophiuchus, Mars (+1.75 to +1.2) in Libra, and Jupiter (-1.7 to -1.8) in Libra are visible before dawn during the first 3 weeks and the latter two will be within 0.2° of one another on the 7th. Saturn (+0.5 to +0.6 in Sagittarius), which will be within less than one degree of Mercury on the 13th, rises higher in the predawn eastern sky during January. The waning crescent Moon passes Mars and Jupiter on the 11th, Saturn on the 14th, and Mercury on the 15th. After passing the Sun at New Moon on the 16th, the waxing crescent Moon passes Venus on the 17th, and Neptune and Uranus respectively on the 20th and 23rd.

PlanetConstellation(s)MagnitudePlanet PassagesTime/Date
SunSagittarius, Capricornus-26.8New Moon9:17PM EST, 1/16
MercuryOphiuchus, Sagittarius-0.2 to -0.5Max. West Elong 22.7°
Saturn 0.6° N
3:00AM EST, 1/1
2:00AM EST, 1/13
VenusSagittarius, Capricornus-3.8Superior Conjunction2:00AM EST, 1/9
MarsLibra+1.5 to +1.2Jupiter 0.2° N4:40AM EST, 1/7
JupiterLibra-1.7 to -1.8Mars 0.2° S4:40AM EST, 1/7
SaturnSagittarius+0.5 to +0.6Mercury 0.6° S2:00AM EST..1/13
NeptuneAquarius+7.9 to +8.0  

January Moon

The New Moon of January is on the 16th at 9:17PM EST. It is the beginning of Lunation 1176 which ends 29.78 days later with the New Moon of Feb. 15th at 4:05PM EST. The first Full Moon of January in Gemini occurs at 9:24PM EST on the 1st. There is a second Full Moon in Cancer in January that coincides with a total lunar eclipse on the 31st at 8:47AM EST which creates a “Blood Moon” appearing to have a red color. Although the Earth will block direct sunlight from reaching the Moon, the atmosphere on the perimeter of the Earth’s shadow will preferentially pass red light and scatter the blue portion of the sunlight which continues through and is reflected back to Earth by the Moon as red light.

The January Moon is known as the “Moon after Yule” or “Wolf Moon”. The Celts called it the “Quiet Moon”, and Colonial Americans called it the “Winter Moon”. Chinese refer to it as “Holiday Moon”, and it was the “Wolf Moon” in Medieval England. Anishinaabe (Odawa and Ojibwe) recognize it as “Manidoo-gizis (Spirit Moon).

Lunar Perigee (closest to Earth) is 222,559 miles or 55.91 Earth radii on the 1st at 4:49PM EST. Perigee (223,068 miles or 56.28 Earth radii) occurs again on the 30th at 4:57AM EST. Apogee (maximum orbital distance) occurs on the 14th at 9:10PM EST when it is at 252,565 miles (63.75 Earth radii).

Both full moons are “Supermoons” because they occur in close proximity to each perigee. Their proximities cause each to be large and bright full moons which produce exceptionally high tides. The January 1st perigee is the closest of 2018 and the Full Moon follows by less than 5 hours. The 2nd Full Moon is not quite as “Super” as the 1st because perigee on the 30th is slightly farther and over 16 hours before Full Moon.

PlanetConstellationMagnitudeMoon PassageMoon PhaseMoon Age
SunSagittarius-26.89:17AM EST, 1/16New0 days
MercurySagittarius-0.21.7°N, 3:00AM EST, 1/15Waning Crescent28.06 days
VenusSagittarius-3.84.1°N, 8:28AM EST, 1/17Waxing Crescent0.84 days
MarsLibra+1.43.9°NNE, 5:03AM EST, 1/11Waning Crescent24.15 days
JupiterLibra-1.74.1°NNE, 12:59AM EST, 1/11Waning Crescent23.98 days
SaturnSagittarius+0.52.8°N, 9:13PM EST, 1/14Waning Crescent27.82 days
UranusPisces+5.84.3°SSE, 8:00PM EDT, 1/23Waxing Crescent6.95 days
NeptuneAquarius+7.91.4°SSE, 3:00PM EST, 1/20Waxing Crescent3.74 days


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