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November 2016 Skies


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November Skies

by Dick Cookman

10/31/2016

 

Highlights: Comet Journal, Martian Landers, Meteor Showers, Polar Reversal?, Planet Plotting, November Moon

Focus Constellations: Camelopardalis, Auriga, Taurus, Perseus, Cassiopeia, Andromeda, Pegasus, Cepheus, Cygnus, Lyra, Draco, Ursa Minor, Ursa Major, Bootes

Comet Journal

Another month of bright and moderately bright comet absence...nothing is expected to exceed 11th magnitude, leaving observation opportunities to those with giant binoculars or telescopes. We await with excited anticipation the appearance of 4 Christmas, winter and Easter comets which may achieve naked eye visibility. These include comets 45P/Honda-Mrkos-Pajdusakova, 2P Enke (see Taurid meteor shower below), V2 Johnson, and 41P/Tuttle-Giacobini-Kresak.

Mars Landers

Opportunity departed from Marathon Valley on the western edge of Endeavour Crater, a basin 14 miles (22 kilometers) in diameter that was excavated by a meteor impact billions of years ago. The rover reached the edge of this crater in 2011 after more than seven years of investigating a series of smaller craters and establishing evidence for acidic ancient water that soaked underground layers and sometimes covered the surface. After extensive study of Marathon Valley, the rover traveled southward along the edge of the crater then descended into the half mile long Bitterroot Valley, a fluid-cut gully trending northeastward which drops into the crater depths. One goal for the new mission assigned to the rover includes examination of the gully to determine if it was cut by water or by mud or debris flows. A second goal is to compare rocks inside Endeavour Crater to the dominant type of sulfate rich rock examined on the plains explored by Opportunity before reaching the crater. The third science goal of the new extended mission is to find and examine rocks from a geological layer that was in place before the impact that excavated Endeavour Crater.

Upon reaching Spirit Mound, a prominent feature near the eastern terminus of Bitterroot Valley, Opportunity commenced investigation of rock exposures next to the mound. The science team has not yet determined whether the mound area will provide rocks old enough to meet the criteria of the third goal.

As of Sol 4521 (Oct. 11, 2016), the solar array energy production is 507 watt-hours. Total distance traveled on Mars is 26.99 miles (43.44 kilometers).

On Sol 1422 (August 5, 2016), after almost 4 years of travel on Mars, Curiosity arrived at the Murray Buttes region of lower Mt. Sharp, the Mt. Rainier size peak in the center of 96 mile wide Gale Crater. On Sol 1469 (Sept. 22, 2016), after detailed examination of the buttes and obtaining a drilling sample at Quela, Curiosity resumed its southeastward trek away from Murray Buttes toward younger rock. The rover veered to the southwest on Sol 1473 in order to avoid the possibility of getting stuck in a black sand dune field blocking the uphill path. Future progress is further jeopardized by lower solar energy availability associated with increasing levels of dust in the windy atmosphere. The steadily declining visibility has raised concern about the possible onset of a global dust storm.

On Sol 1489-90, October 12, 2016, the rover reached a location which was 100 meters above the site where the Murray Formation was first encountered. In the last 2 years the rover made amazing progress as it ascended the slope exposing the lower 100 meters of the rock layer forming the base of Mount Sharp, an incredible thickness of primarily lacustrine (lakebed) sedimentary rock!

On Sol 1491 (Oct. 16, 2016), Curiosity started preparation for another drilling project. The rover dumped the sample from Quela and observed that the wind moved the dump pile overnight for 2 consecutive days before the APXS was able to measure its chemical composition. On the 19th (Sol 1495), another drilling sample at Sebina was obtained before resuming the upward journey on Sol 1500 (Oct. 24, 2016). Numerous rock outcrops were examined and panoramic images obtained during the ensuing days as Curiosity traveled another 138 meters by Oct. 30th (Sol 1506) over a rising slope of rough terrain characterized rounded bedrock knobs and pointed pinnacles and dotted by slabs of Murray formation bedrock and boulders.

Meteor Showers

Two Meteor Showers dominate November—the relatively weak (<10 meteors/hour) northern Taurids (Nov. 12) from Comet Enk, and the Leonids (Nov. 17) from Comet 55P Temple-Tuttle. Dimmer meteors of each will be lost in the glare of the gibbous Moon. The Leonids have produced impressive meteor storms of up to 40 meteors per second, but the 2016 shower is expected to produce fewer than 20 per hour.

Polar Magnetic Reversal?

Numerous scientists have interpreted recent changes in the intensity of Earth's magnetic field as potential evidence for a polar reversal in the near future. The last polar reversal was almost 800,000 years ago, and polar reversal frequency has averaged about 200,000 to 300,000 years over the last few million years. Some experts conclude that we are overdue. Geologic evidence for microbial extinction events associated with magnetic reversals escalates concern because magnetic intensity may decrease to zero during the interval of the reversal causing Earth's surface to be subjected to intense bombardment by radiation from solar and cosmic sources. We are not certain about how long it takes for completion of a reversal.

Current theories as to reversal cause include the concept that the magnetic field is generated by convection cells in the outer liquid iron core of Earth. The rotation direction of these cells may control polarity of the magnetic field and may reflect relative rotation rates of the lower mantle and outer core. If the mantle is rotating faster than the core, the rotation direction of the cells will be opposite to that produced when it is rotating slower.

Recent measurements reveal that although the magnetic field intensity is decreasing, it is currently much higher than the long term average. At current rates, it will take 1000 years to drop to the long term average.

Planet Plotting

Mercury (-1.4 to -0.5) rises in Libra with the Sun at the beginning of the month after its October conjunction with the Sun. It dims as it rises later and appears higher in the sky each evening in November. On the 23rd, Mercury will appear slightly over 3° south of Saturn after sliding between Saturn and the 1st magnitude red supergiant Antares in Scorpius during previous evenings. Venus (-4.0 to -4.1) is visible in the southwestern sky after sunset in November and is approaching its best appartition of the year in December. It will move from Ophiuchus to Sagittarius and rise higher in the sky each evening of the month. Venus is below dimmer Saturn on the 1st and south of Saturn and a waxing crescent Moon on the 2nd. It will draw away from the ringed planet as it moves southward toward Mars in November. Saturn (+0.6 to +0.5) and Mars (+0.3 to +0.5) flank Venus in the southwestern sky after sunset. Mars will move southward slightly slower than Venus as both rise higher in the sky during November. Earth is orbiting away from Mars and Venus is catching up to Earth in its orbit.

Neptune (+7.9) in Aquarius and Uranus (+5.7) in Pisces are in the southern sky after sunset and set after midnight. Uranus moved through opposition last month and will gradually grow dimmer.

Jupiter (-1.7) rises in Virgo about 3 hours before the Sun on the 1st and after 2AM EST on the 30th.

PlanetConstellationMagnitudePlanet Passages
SunLibra, Scorpius-26.8New Moon, 11/29, 7:18AM EST
MercuryLibra, Scorpius, Ophiuchus-1.4 to -0.5Saturn, 3.4°N, 11/23 , 11AM EST
VenusLibra, Scorpius, Ophiuchus-4.0 to 4.1 
MarsSagittarius, Capricornus+0.3 to +0.5 
JupiterVirgo-1.7 
SaturnOphiuchus+0.6 to +0.5Mercury, 3.4°S 11/23, 11AM EST
UranusPisces+5.7 
NeptuneAquarius+7.9 

November Moon

The New Moon of November is on the 29th at 7:18AM EST. The New Moon is the beginning of Lunation 1162 which ends 29.77 days later with the New Moon of December 29th at 1:53AM EST.

The Full Moon in November in Pisces occurs at 8:52AM EST on the 14th. It is called the "Beaver Moon", a term inherited from our colonial American forebears. The Celts called it the "Dark Moon", and on the other side of the Earth the Chinese refer to the November Moon as the “Whit,e Moon". Medieval English thought of it as the “Snow Moon” and the Anishinaabe (Odawa and Ojibwe) people of northern Michigan recognize it as “Gashkadino-giizis(oog)” (Freezing Moon).

Lunar perigee distance (closest to Earth) is 222,524 miles or 55.90 Earth radii on the 14th at 6:21AM EST, the closest perigee of the year. Full Moon occurs 2.5 hours later, producing the largest "Supermoon" of the year. The Full Moon lineup of the Sun, Earth, and a nearby Moon will force seaside residents to be on the alert for unusually high tides which will also result in higher than normal "tidal bore waves" moving farther upstream in rivers draining into the sea. The Moon is at the apogee position in orbit (maximum orbital distance) at 252,621 miles (63.74 Earth radii) from Earth on the 27th at 3:08PM EST.

Cecil Adams' reasons why we need the Moon:
"Reason #1: It got rid of primordial pollution. The moon most likely formed when some smaller planet struck Earth about 4.5 billion years ago, ejecting chunks of debris that eventually coalesced in orbit. Crucially, this collision may also have stripped away a thick proto-atmosphere that was trapping the heat of Earth’s molten surface. Without this rather violent development we might have ended up like Venus, where life is only imaginable by Ray Bradbury."

PlanetConstellationMagnitudeMoon PassageMoon Phase/Age
SunScorpius-26.87:18AM EST, 11/29New ~ 0 days
MercuryOphiuchus-0.57.0°N,11PM EST, 11/30Waxing Crescent ~ 1.65 days
VenusOphiuchus-4.07.0°N, Midnight EDT, 11/2Waxing Crescent ~ 2.43 days
MarsSagittarius+0.45.0°N, 7AM EST, 11/6Waxing Crescent ~ 6.72 days
JupiterVirgo-1.71.9°N, 9AM EST, 11/24Waning Crescent ~ 24.81 days
SaturnOphiuchus+0.54.0°N, 3PM EDT, 11/2Waxing Crescent ~ 3.06 days
UranusPisces+5.73.0°S, 6AM EST, 11/12Waxing Gibbous ~ 12.68 days
NeptuneAquarius+7.81.0°N, 10AM EST, 11/9 Waxing Gibbous ~ 9.85 days


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