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October Skies

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October Skies

by Dick Cookman


Highlights: Comet Journal, Martian Landers, Meteor Showers, Quiet Sun, Planet Plotting, October Moon

Focus Constellations: Hercules, Lyra, Aquila, Cygnus, Pegasus, Pisces, Aries, Andromeda, Perseus, Taurus. Auriga, Camelopardalis, Ursa Major, Draco, Ursa Minor, Cepheus, Cassiopeia

Comet Journals

C/2018 W2 (Africano) is moving southward through Pisces, Aquarius, and Pisces Austrinus in October. It was at perihelion on September 5, 2019, and closest to Earth on the 27th when it reached 8th magnitude. It will retain current brightness throughout October.

C/2018 N2 (ASASSN), an 11th magnitude comet moving through Andromeda and Pegasus in October, rises before sunset and sets before sunrise. It will slowly move through northern skies for the next two years, reaching perihelion on November 11 in Andromeda. Comet 260P/McNaught is an 11th magnitude comet. It is circling through Perseus in October and will be closest to Earth on October 4. It is at perihelion on the 8th.

Comet C/2017 T2 PanSTARRS is in Auriga at magnitude 11. It will be closest to Earth on December 29 and reaches perihelion in May 2020.

Mars Landers

The Insight lander, at its landing site on Elysium Planita and carrying the Heat Flow and Physics Properties Package (HP3), recently placed its robotic arm next to the self hammering heat probe which is stuck at a depth of 14 inches and is unable to dig deeper on its own.

Mission scientist plan to use the robotic arm to “pin” the probe, known as the “mole” against the side of the hole already dug in order to increase friction and hopefully permit deeper digging. Currently they think that the “mole” recoils from each hammer blow, causing it to bounce in place. If the robotic arm pressure in enough, increased friction between the “mole” and the side of the hole may allow it to overcome the unique soil characteristics which halted the “mole” in the first place. If successful, they plan to burrow down to a depth of 16 feet to record heat flow from the interior.

The Curiosity rover is in Glen Torridon, the clay-bearing unit in the valley adjacent to Vera Rubin Ridge on 16,404 foot Mt. Sharp at the center of Gale Crater. After drilling at Glen Etive 1 in early August, the drilling powder was delivered to SAM for gas chromatograph and mass spectrometer analysis on Sol 2500 (8/16/19). The balance of August was devoted to preparation for the solar conjunction of Mars of 9/2/19 when Mars was on the opposite side of the Sun and out of radio communication with Earth for two weeks.

Following conjunction, preparations proceeded for drilling at Glen Etive 2 on Sol 2525 (9/12/19) which culminated with a successful 23rd hole drilled on Mars by the Curiosity rover on Sol 2528. The last half of the month was devoted to further observations at Glen Etive 2, including remote sensing of the surroundings and potential future targets, sample preparation for further testing, and preparation for a rare wet chemical analysis of the drilling powder obtained at Glen Etive 2.

Meteor Showers, Asteroid Surprises

The best showers in October are the Orionids which will suffer from interference by the waning crescent Moon. Try to block out the Moon with a building or tree to enhance views of the meteors emanating out of Orion in the hours before dawn.

  • October 1: Alpha Aurigids. Active Aug. 25-Sep. 5. Radiant 5h36m +42°. ZHR 10. 66 km/sec. Waxing Crescent Moon. Progenitor: Comet Keiss.
  • October 8 - 9: Draconids Active Oct. 6-Oct 10. Radiant 17h28m +54°. ZHR variable. 20 km/sec. Waxing Gibbous Moon. Progenitor: Asteroid 2009 WN25.
  • October 18: Epsilon Geminids. Active Oct. 14-Oct. 27. Radiant 6h48m 27°. ZHR 2. 70 km/sec. Waning Gibbous Moon. Progenitor: ?
  • October 20: Orionids. Active Oct. 2-Nov. 7. Radiant 6h20m 16°. ZHR 20. 66 km/sec. Waning Gibbous Moon. Progenitor: Comet 1P/Halley

Nine meter wide Asteroid 2019 TE passed slightly more than 200,000 miles from Earth at 20 km/s/sec on September 28. On the 29th, 5 meter wide Asteroid 2019 TD passed within 70,000 miles of Earth at 10 km/s, and Asteroid 2018 SM8, also 5 meters wide, passed at less than 100,000 miles on October 1, traveling at 14km/s.

Quiet Sun

The Sun is a variable star. The current sunspot minimum coincides with lower levels of solar wind which has a reduced capacity to counteract cosmic rays thus subjecting Earth to increased bombardment.

During the 19th and 20th centuries, Earth typically was slightly cooler during minimums in the 9 to 11 year sunspot cycle and warmer when sunspots were abundant. This may be related to higher levels of ultraviolet light emitted by the Sun during maximums. The last peak was in 2014 during Cycle 24 when maximum sunspot levels reached 140. Previous peaks (Cycles 20 through 23) were in 1959, 1969, 1979, 1988-1989, and 2000 when levels approached or exceeded 200. The current low (# of sunspots = 0) was preceded by sunspot minimums during 2008-2009, 1996-1997, and 1985-1986. Sunspot absence in the current minimum probably eliminates solar variation as a factor in recent elevated global temperatures, as does the lower sunspot numbers during the last peaks when compared to peaks in the latter part of the 20th century.

Earlier extended minimums include the period from 1790 to 1820 known as the Dalton Minimum, the 70 year Maulder Minimum between 1645 and 1715, the Sporer Minimum between 1450 and 1540, and Wolf Minimum of 1230 to 1320. All four were characterized by unusually cool temperatures in Europe during the “Little Ice Age”.

Extended minimums were repeated every 100 to 150 years in the last millennium, so some projections for the current minimum raise the specter of an extended episode possibly rivaling the 30 to 90 year intervals listed above. Solar type stars share this type of variation with the Sun. Whether this leads to counteracting or partially blunting climatic change is in the eye of the beholder until it happens, or when additional relevant data is obtained.

Planet Plotting

October morning planets include Neptune (+7.8) in Aquarius, Uranus (+5.7) in Aries, and Mars (+1.8) in Virgo. Neptune, in the southeastern sky in the early evening, sets about 4:00AM EDT. Uranus is at opposition on the 28th and is visible throughout the night. Mars was in conjunction with the Sun last month. It will rise before dawn in late October and will be 7° above the eastern horizon on the 31st. It will increase brightness as Earth catches up to it in orbit during the next year until reaching opposition.

Jupiter (-1.9 to -1.7) in Ophiuchus and Saturn (+0.5 to +0.6) in Sagittarius are bright evening planets in southern skies, rising after the Sun and setting about 10:00PM EDT and 11:30PM EDT respectively. Mercury (-0.2 to +0.7 ) and Venus (-3.8) in Virgo and Libra are low in the southwestern sky after sunset on the 1st and rise higher during the month. Venus is closer to the horizon on the 1st and closes the gap with Mercury and is within 3° when the two are in conjunction on the 30th.

The waxing crescent Moon is 1.9° from Jupiter at 4:00PM EDT on the 3rd, 4.0° from Venus at 10:00AM EDT on the 29th, and 7.0° from Mercury at 11:00AM EDT on the 29th. The waning gibbous Moon is 4.0° from Uranus at 8:00PM EDT on the 14th. The waning crescent Moon is 5.0° from Mars at 1:00PM EDT on the 26th, and the waxing gibbous Moon is 0.03° from Saturn at 5:00PM EDT on the 5th and 4.0° from Neptune at 7:00PM EDT on the 10th.

PlanetConstellation(s)MagnitudePlanet PassagesTime, Date
SunVirgo-26.8New Moon11.39PM EDT, 10/27
MercuryVirgo, Libra-0.2 to +0.7Max. East Elongation
Venus, 3.0°N
Midnight EDT, 10/19
4:00AM EDT, 10/30
VenusVirgo, Libra-3.8Mercury, 3.0°S4:00AM EDT, 10/30
MarsVirgo, Libra+1.8  
JupiterOphiuchus-1.9 to -1.8  
SaturnSagittarius+0.5 to +0.6  
UranusAries+5.7Opposition4:00AM EDT, 10/28

October Moon

October’s New Moon on the 27th at 11:39PM EDT is the beginning of Lunation 1198 which ends 28.43 days later with the New Moon of November on the 26th at 10:06AM EST.

The October Full Moon is on the 13th at 5:08PM EDT. It is known as the “Hunter’s Moon” because colonial American farmers hunted game in the stubble of their harvested fields in its light to provide meat for the coming winter. The “Hunter’s Moon” rises near sunset for almost as many nights in a row as did the “Harvest Moon” in September because moonrise advances less than the normal 50 minutes a day. Celts called it the “Harvest Moon” and it was named the “Blood Moon” in Medieval England. Chinese call it the “Kindly Moon” and the Anishinaabe (Odawa and Ojibwe) people recognize it as “Binaakwe-giizis” (Falling Leaves Moon.)

Lunar Apogee (maximum orbital distance) occurs on the 10th at 2:29PM EDT when the Moon is at 252,214 miles (63.64 Earth radii). Perigee occurs on the 26th at 6:39AM EDT when the Moon is at a distance of 224,508 miles (56.65 Earth radii).

PlanetConstellationMagnitudeMoon PassagesMoon Phase, Moon Age
SunLibra-26.811:39PM EDT, 10/27New, 0 days
MercuryLibra+0.47.0°N, 11:00AM EDT, 10/29Waxing Crescent, 1.47 days
VenusLibra-3.84.0°N, 10:00AM EDT, 10/29Waxing Crescent, 1.438 days
MarsVirgo+1.85.0°NNE, 1:00PM EDT, 10/26Waning Crescent, 29.94 days
JupiterOphiuchus-1.91.9°N, 4:00PM EDT, 10/3Waxing Crescent, 5.07 days
SaturnSagittarius+0.50.03°S, 5:00PM EDT, 10/5Waxing Gibbous, 7.11 days
UranusAries+5.74.0°S, 8:00PM EDT, 10/14Waning Gibbous, 16.23 days
NeptuneAquarius+7.84.0°S, 7:00PM EDT, 10/10Waxing Gibbous, 12.19 days


Oct 11 2019 04:57 AM

Highlights: Comet Journal, Martian Landers, Meteor Showers, Quiet Sun, Planet Plotting, October MoonFocus Constellations: Hercules, Lyra, Aquila, Cygnus, Pegasus, Pisces, Aries, Andromeda, Perseus, Taurus. Auriga, Camelopardalis, Ursa Major, Draco, Ursa Minor, Cepheus, Cassiopeia

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Yes, our wonderful Autumn/Winter skies are upon us again. 

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