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March 2018 Skies

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March Skies

by Dick Cookman


Highlights: Comet Journal, Martian Landers, Meteor Showers/Vernal Equinox, Planet Plotting, March Moon

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

Comet Journal

No bright comets are expected for the next few months. The brightest is unlikely to exceed 11th or 10th magnitude. An example is 10th magnitude C/2016 R2 (PanSTARRS) which is currently slowly moving northward between Auriga and Perseus, and will grace northern skies for the next 4 years. It will pass through perihelion in May and remain at 10th or 11th magnitude until June.

Mars Landers

Opportunity is about half way 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.

Opportunity’s latest surprises include observations of possible "rock stripes.” The stripes consist of color bands and rock & gravel bands paralleling the slope and may result from erosion/deposition by wind blowing from the crater floor to the rim. Similar bands on Earth form as a result of freeze/thaw episodes associated with snow/ice formation and melting in sloped areas. The bands on Mars may result from similar activity since the axis of Mars cycles through a larger variation in tilt than Earth does, causing greater climate extremes with warmer and colder periods. Hundreds or thousands of years ago Mars may have been warmer and wetter, experiencing winters with more extensive snow cover and the associated freeze/thaw cycles. As of Sol 5004 (Feb. 20, 2018) the solar array energy production was 653 watt-hours. Total travel on Mars is 28.03 miles (45.12 kilometers.)

After ascending the ~200 foot “Vera Rubin Ridge” in the latter part of 2017, Curiosity crossed the ridge and reached the low-lying area south of “Vera Rubin Ridge” called the “Clay Unit” or the “Phyllosilicate Trough” on Sol 1950 (Jan. 30, 2018.) At a site dubbed “Jura,” the science laboratory observed an exposure of finely laminated bedrock with tiny crystal-shaped bumps plus mineral veins with both bright and dark material. The bumps appear similar to gypsum crystals on Earth which form as water evaporates from saline water bodies. Scientists are now investigating if the crystals formed during or after formation of the rock layer. The former points to evidence of a drying lake and the latter to groundwater flowing through the sediment after it became cemented into rock. The rock layers also show color variations, smoothly horizontal laminations thickness varying more than ten times in individual layers, and a more than four times variation in the iron content. They also include stick-shaped features the size of rice grains and mineral veins with both bright and dark zones.

Meteor Showers, Vernal Equinox

The Gamma Normids in mid-March are the best periodic shower of the month but are restricted to the southern hemisphere. March provides excellent views of sporadic meteors and the zodiacal light.

Debris from comets and asteroids which passed through Earth’s neighborhood in the past is scattered throughout the inner solar system as a pancake shaped cloud centered on the Sun and the plane of the Solar System. Earth orbits through the debris like a traveler plowing through a dust storm. After the Sun sets near the March Equinox on Mar. 20th at 12:15PM EDT, scattered sunlight from the faintly illuminated debris produces the diffuse zodiacal light which appears as a glowing equilateral triangle with a base centered on the sunset point. It is best observed near the equinox because the path of the setting Sun makes a steeper angle with the horizon than at most other times of the year, reducing its interference with the zodiacal light.

Planet Plotting

Venus (-3.8) in Aquarius, Pisces, and Aries has moved into the evening sky with Mercury (-1.2 to +5.1) in Aquarius and Pisces in tow. The two inner planets are separated by just 1.0° on the 4th and under 4.0° on the 19th. Mercury passes through Maximum Eastern Elongation (18.4° from the Sun) on the 15th and rapidly descends into the glow of sunset as it approaches within 11° of Uranus (+5.9) in Pisces on the 22nd. Venus rises higher in the western evening sky and has a very close encounter with Uranus on the 28th when they are less than 0.01° apart. Neptune (8.0) in Aquarius is at Solar Conjunction on the 4th and will appear in dawn skies at month’s end.

Jupiter (-2.0 to -2.2) in Libra, Mars (+0.8 to +0.3) in Ophiuchus and Sagittarius, and Saturn (+0.6 to +0.5) in Sagittarius are also morning planets with Jupiter rising about midnight. On March 1, at 3:00AM EST, Jupiter, Antares (the stellar rival of Mars the War God,) Mars, and Saturn will be spaced equally along the ecliptic through the southeastern sky. All three brighten in March as Mars appears to move away from Antares and Jupiter, approaching Saturn until the two are separated by less than 2.0° in early April.

PlanetConstellation(s)MagnitudePlanet PassagesTime, Date
SunCapricornus, Aquarius-26.8New Moon9:12AM EDT, 3/17
MercuryAquarius, Pisces-1.2 to +5.1Venus, 1.1°SE
Max. East Elongation
Venus, 3.8°SSE
Uranus, 10.8E
1:00AM EST, 3/4
11:00AM EDT, 3/15
4:00AM EDT, 3/19
4:00AM EDT, 3/28
VenusAquarius, Pisces, Aries-3.8Mercury, 1.1°NW
Mercury, 3.8°NNW
Uranus, 0.07NNE
1:00AM EST, 3/4
4:00AM EDT, 3/19
9:00PM EDT, 3/28
MarsOphiuchus, Sagittarius+0.8 to +0.3  
JupiterLibra-2.0 to -2.2  
SaturnSagittarius+0.6 to +0.5  
UranusPisces+5.9Mercury, 10.8°W
Venus, 0.07°SSE
4:00AM EDT, 3/22
9:00PM EDT, 3/28
NeptuneAquarius+8.0Solar Conjunction9:00AM EST, 3/4

March Moon

March’s New Moon is on the 17th at 9:12AM EDT. It is the beginning of Lunation 1178 which ends 29.49 days later with the New Moon of April 15th at 9:57PM EDT. The full moons of March start and end the month. They are on the 1st at 7:51PM EST and on the 31st at 8:37AM EDT. The Full Moon on the 31st is a “Blue Moon” by both common definitions as follows: It is the 2nd full moon in the month of March and is the 4th full moon in the 1st quarter of 2018.

The March Moon is known as the “Egg Moon,” “Grass Moon,” “Easter Moon,” or “Paschal Moon.” The Celts called it the “Moon of Winds” and Colonial Americans called it the “Fish Moon.” Chinese refer to it as the “Sleepy Moon” and it was the “Chaste Moon” in Medieval England. Anishinaabe (Odawa and Ojibwe people) recognize it as “Onaabani-giizis (Snowcrust Moon.)

Lunar Perigee (closest to Earth) is 229,352 miles or 57.87 Earth radii on the 26th at 1:17PM EDT. Apogee (maximum orbital distance) occurs on the 11th at 5:14AM EDT when it is at 241,455 miles (63.45 Earth radii).

PlanetConstellationMagnitudeMoon PassageMoon Phase, Moon Age
SunPisces-26.89:12AM EDT 3/17New, 0 days
MercuryCapricornus+0.47.3°SSE, 7:00PM EDT, 3/18Waxing Crescent, 1.41 days
VenusPisces-3.83.5°SSE, 6:00PM EDT, 3/18Waxing Crescent, 1.37 days
MarsOphiuchus+0.73.8°N, 8:00PM EST, 3/9Waning Crescent, 22.16 days
JupiterLibra-2.14.0°N, 2:00AM EST, 3/7Waning Crescent, 19.41 days
SaturnSagittarius+0.62.2°N, 9:00PM EST, 3/10Waning Crescent, 23.20 days
UranusPisces+5.94.4°SSE, 3:00PM EDT, 3/19Waxing Crescent, 2.24 days
NeptuneAquarius+8.01.7°SSE, 10:00AM EDT, 3/16Waning Crescent, 28.75 days

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