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February 2018 Skies


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February Skies

by Dick Cookman

01/31/2018


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

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

Comet Journal

C/2017 T1 (Heinze) is rapidly descending through western Pegasus in the southwestern evening sky. It reached 9th magnitude when closest to Earth on Jan. 5th and has since decreased to 11th magnitude. It will be at perihelion (closest to the Sun) on Feb. 21st and will st ay at 11th magnitude throughout February. No other comet is expected to be brighter 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 rover entered the valley on May 15, 2017 (Sol 4720) and is engaged in determining how the boulder lined channel was cut into the side of the crater. Primary candidates so far include water erosion and erosion by mud or debris flows. Although evidence to date does not favor either mechanism, mission scientists hope that deposits at the valley terminus may provide additional clues.

During the November solstice Opportunity survived temperatures below -140°F. It is continuing its program of panoramic imaging of “Perseverance Valley” and arrived at a location upstream of a fork in the channel on Dec. 10th (Sol 4934). Robert Frost provided no usable input about which fork to take as each was less traveled. After 3 weeks of collecting Panoramic Camera (Pancam) color stereo imagery and Alpha Particle X-ray Spectrometer (APXS) data, mission scientists pondered the evidence and decided on the north fork. On Sol 4958 (Jan. 3, 2018), Opportunity drove about 13 feet (4 meters) in that direction. and devoted the next few sols to remote sensing. The Alpha Particle X-ray Spectrometer (APXS) was used on Sol 4961 (Jan. 6, 2018) to keep the rover state as stable as possible. Meanwhile, the batteries were tested with the Zero Degree Heater (ZDH).

Solar array energy production increased from 420 to 624 watt-hours per sol as wind cleaned dust from the solar collectors. As of Sol 4977 (Jan. 23, 2018), Opportunity achieved a total distance traveled on Mars of 28.02 miles (45.09 kilometers).

On Sol 1809 (9/15/17), Curiosity began its ~200 foot ascent of Vera Rubin Ridge and completed it on Sol 1874 upon reaching the boundary between the lower light colored cliff forming rock layer and the darker upper layer observed from orbit. The dark layer covers most of the ridge with a broad gentle uphill slope. Since rock layers vary in color due to differences in chemical content which can be attributed to processes associated with original deposition and post deposition alteration, the next 76 sols were devoted to detailed examination of the rocks, sand, and exposed rock outcrops comprising the upper dark layer. On Sol 1950 (Jan. 30, 2018) Curiosity reached the low-lying area south Vera Rubin Ridge called the Clay Unit or the Phyllosilicate Trough due to detection of clay minerals from orbit.

Meteor Showers

The Alpha Centaurids and Beta Centaurids are February's best meteor showers for southern hemisphere observers. The source of the meteors is debris shed from Comet 169P/NEAT which at perihelion in 2014 and will return this year in April. The showers peak on the night of the 8th & 9th during the waning crescent phase of the Moon. The showers may exhibit some fireballs and can achieve meteor rates of 25+ per hour shooting up from the SSW horizon well before dawn for those favored with clear skies without significant light pollution. Northern observers will have difficulty seeing this shower but may view the minor Delta Leonid shower culminating at 5 to 10 meteors per hour after the waxing gibbous Moon sets before dawn on the 24th.

Planet Plotting

Venus (-3.8) and Mercury (-0.5 to -1.3) in Capricornus and Aquarius are lost in the glow of sunset until February 21st when Neptune (+0.8) in Aquarius is within 1° of Venus. Before its Superior Conjunction with the Sun on the 17th, the Moon passes Mercury and the Sun at New Moon on the 15th. The Waxing Crescent Moon then passes Venus and Neptune on the 16th and Uranus (+5.9) in Pisces on the 20th.

Mars (+1.2 to +0.8) rises before the Sun in Scorpius and Ophiuchus, as does Jupiter (-1.8 to -2.0) in Libra. Saturn (+0.6 in Sagittarius) is closer to the eastern horizon before dawn. The Waning Crescent Moon passes Jupiter on the 7th, Mars on the 9th. and Saturn on the 10th.

PlanetConstellation(s)MagnitudePlanet PassagesTimeDate
SunCapricornus, Aquarius-26.8New Moon4:06PM EST2/15
MercuryCapricornus, Aquarius-0.5 to -1.3Superior Conjunction
Neptune, 0.43°NNW
7:00AM EST
8:00AM EST
2/17
2/25
VenusCapricornus, Aquarius-3.8Neptune, 0.54°NNW2:00PM EST2/21
MarsScorpius, Ophiuchus+1.2 to +0.8   
JupiterLibra-1.8 to -2.0   
SaturnSagittarius+0.6   
UranusPisces+5.8 to +5.9   
NeptuneAquarius+8.0Venus, 0.54°SSE
Mercury, 0.43°SSE
2:00PM EST
8:00AM EST
2/21
2/25

February Moon

The New Moon of February is on the 15th at 4:06PM EST. It is the beginning of Lunation 1177 which ends 29.78 days later with the New Moon of Mar. 17th at 9:13AM EDT. The Full Moon of February is absent, there is no Full Moon in February. There were two in January and will be two in March, on the 1st and 31st each month. “Black Moon” is the popular term for a month with no full moon.

Black Moons occur only in February and over a period of almost 19 years known as the Metonic Cycle which compares the length of time between successive new moons and the period of time between Spring Equinoxes. There are 19 tropical years and 235 lunar cycles each occur in a little more than 6939 days.

Some Native American groups celebrated 13 moons per year as opposed to the twelve currently recognized. Since lunar months average 29.53+ days long, there are almost 12.37 lunar months per year, making everyone right part of the time on the average.

Lunar Perigee (closest to Earth) is 226,137 miles or 57.06 Earth radii on the 27th at 9:36AM EST. Apogee (maximum orbital distance) occurs on the 11th at 9:00AM EST when it is at 252,090 miles (63.61 Earth radii).

PlanetConstellationMagnitudeMoon PassageMoon PhaseMoon Age
SunCapricornus-26.84:06PM EST 2/15New0 days
MercuryCapricornus-0.21.1°NNW, 1:00AM EST, 2/15Waning Crescent29.15 days
VenusAquarius-3.80.5°N, Midnight EST, 2/16Waxing Crescent0.33 days
MarsOphiuchus+1.44.3°N, 2:00AM EST, 2/9Waning Crescent23.70 days
JupiterLibra-1.74.1°NNE, 5:00PM EST, 2/7Waning Crescent21.82 days
SaturnSagittarius+0.52.5°N, 10:00PM EST, 2/10Waning Crescent25.03 days
UranusPisces+5.84.4°SSE, 6:00AM EDT, 2/20Waxing Crescent4.58 days
NeptuneAquarius+8.01.6°SSE, 11:00PM EST, 2/16Waxing Crescent1.29 days


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