Jump to content


- - - - -

October 2018 Skies

Discuss this article in our forums

October Skies

by Dick Cookman



Highlights: Comet Journal, Martian Landers, Meteor Showers, Planet Plotting, Hallowe’en, October Moon

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


Comet Journal

Comet 21P/Giacobini-Zinner (2018) is a 7th magnitude predawn comet which moves through Canis Major in October after passing through perihelion in early September. The comet is the parent of the Draconid Meteor shower which is expected to occur on October 8/9. The Draconids aren’t normally outstanding but material shed during passage of the parent comet may enhance the shower this year. Comet 46P/Wirtanen (2018) is in southern hemisphere skies between Sculptor and Fornax and is approaching 8th magnitude. It has the potential to be a bright Christmas Comet (~ 4th magnitude) as it reaches perihelion on Dec. 12th in Taurus and is closest to Earth 4 days later. It is a short period (5.5 years) comet from the asteroid belt.

Mars Landers

The planet-encircling dust storm on Mars, which was first detected May 30 and halted operations for the Opportunity rover, continues to abate. “The Sun is breaking through the haze over Perseverance Valley, and soon there will be enough sunlight present that Opportunity should be able to recharge its batteries,” said John Callas, Opportunity project manager at JPL. While recovery of the rover is uncertain, the rover team is cautiously optimistic, knowing that Opportunity has overcome significant challenges during its 14+ years on Mars. The rover lost use of its left-front steering in June of 2017, and right front in 2005. Its 256-megabyte flash memory is no longer functioning and the team also knows that everything about the rover is well beyond its warranty period. Both Opportunity and its twin rover, Spirit, were constructed for 90-day missions (Spirit lasted 20 times longer and Opportunity is going on 60 times). The rovers were designed to travel about 1,000 yards, and Opportunity has logged more than 50,000 yards.

Curiosity’s successful drilling attempt on target Stoer was completed by Sol 2138 (Aug 13th). Since the repaired drill is now operated with an immobile feed mechanism in the extended position, delivery of the drilling samples to the CheMin and SAM instruments is somewhat challenging. Mission scientists determined on Sol 2150 that the first part of the sample was delivered incorrectly because delivery of precise portions of drill tailings is not as accurate as when the feed worked properly. Successful delivery of the drilling sample achieved on Sol 2155 permitted detailed chemical analysis to ensue. Since Sol 2138, Curiosity examined the surrounding terrain using its remote instrument package, performed contact science in the immediate vicinity to understand the composition and physical nature of the bedrock, and performed power-intensive lab-quality analyses of the Stoer sample using its onboard analytical instruments. The rover departed from the Stoer location on Sol 2157 and drove toward an interesting grey colored patch of bedrock identified from orbit and referred to as Loch Eriboll. It is within the Jura member of the Murray Formation on the Vera Rubin Ridge, Four bedrock targets ("The Law," "Eathie," "The Minch,” and "Windy Hills”) were selected to show how the gray bedrock differs from the surrounding tan colored rocks. The ChemCam will be utilized to monitor compositional variation, accompanied by Mastcam documentation of those targets. Mastcam mosaics are being acquired which will include multiple filters to look at the spectral properties of the different rocks of both the Laithach area which has a potential contact between the gray and tan rocks, and the Loch Eriboll area. Curiosity will then move to the new potential drill location.

Meteor Showers

According to Guy Ottewell’s 2018 Astronomical Calendar, October skies bring the following meteor showers:

  • Oct. 6 SAT.: Camelopardalids. ZHR ~5. 3 days before New Moon.
  • Oct. 9 Tue.: Draconids. Active Oct 6-10. ZHR ~20. Near New Moon. Very favorable.
  • Oct. 10 Wed.: Southern Taurids. Active Sep 10-Nov 20. ZHR ~5. 1 day after New Moon.
  • Oct. 21 SUN.: Orionids. Active Oct 2-Nov 7. ZHR ~25. 4 days before Full Moon. Quite favorable.

The Orionids and Draconids are best with ~25 and ~20 meteors per hour respectively in dark skies lacking light pollution.

Planet Plotting

Crescent Venus (-4.4 to -4.0) is in Libra and Virgo in October and is still 2° above the horizon a half hour after sunset. The waxing crescent Moon will be 13.0° north of Venus on the 10th at Midnight EDT and northwest of Venus that evening. On the 14th, Venus will be about 7° south of Mercury and on the 26th it will be at inferior conjunction with the Sun. The waxing crescent Moon will be 5.5° north-northeast of Mercury on the 10th at 11:00AM EDT. Mercury (-0.8 to -0.1) will be low in the West after sunset in late October and will be 3.0° south of Jupiter at Midnight on the 29th. Jupiter (-1.7 to -1.6) is in Libra in the western evening sky. The waxing crescent Moon is 4° north of Jupiter on the 11th. Saturn (+0.5 to +0.6) in Sagittarius is low in the Southwest after sunset and sets in the latter part of the evening. The waxing gibbous Moon passes within 2° of Saturn on the 14th.

Mars (-1.3 to -0.6) decorates the evening southern sky in Capricornus in October. It is not as bright as it was at opposition this summer but still presents a bright orange apparition in October. The planet-wide dust storm which drastically degraded telescopic views this summer has settled down, revealing the icecaps and numerous dark mare and sinus surface features. A waxing gibbous Moon will be 5° north of Mars in the southern sky on the 18th. Best viewing for Mars is in early October in the early evening. Later in the month, Mars will appear closer to the southwestern horizon in early evening and glare from the Moon will become more of an issue.

Neptune (+7.8) in Aquarius and Uranus (+5.7) in Aries rise before sunset. The waxing gibbous Moon passes within 2° of Neptune on the 20th and 5° from Uranus on the 24th.

PlanetConstellation(s)MagnitudePlanet PassagesTime,Date
SunLeo, Virgo-26.8New Moon11:47PM EDT,10/8
-0.8 to -0.1Venus, 7.0° S
Jupiter, 3.0° N
11:00AM EDT,10/14
VenusLibra, Virgo-4.4 to -4.0Mercury, 7.0° N
Inferior Conjunction
11:00AM EDT,10/14
10:00AM EDT,10/26
MarsCapricornus-1.3 to -0.6  
JupiterLibra-1.7 to -1.6Mercury, 3.0° SMidnight,10/29
SaturnSagittarius+0.5 to +0.6  
UranusAries+5.7Opposition9:00PM EDT,10/23


Halloween, formerly recognized as “All Hallows E’en” or “Hallows Eve,” is the eve of All Saints’ Day (Nov. 1st.) All Souls’ Day follows on the 2nd. Each day celebrates the 4th cross-quarter day of the year. Cross-quarter days are approximately half way between the equinoxes and solstices and are occasions for recognition of other holidays like Candlemas/Groundhog Day (1st cross-quarter day) and May Day (2nd cross-quarter day). Samhain, the Celtic New Year celebrated with a feast on Nov. 1st, was the Day of the Dead, a Druid holiday which paid homage to ancestors and the souls of loved ones who have died. Celts associated the low altitude of the Sun and cold weather with the dying of the year and with dark spirits prowling through the evening dusk. Halloween is our annual revival of their ancient rituals which preceded the Christianization of the holiday.

October Moon

October’s New Moon on the 8th at 11:47PM EDT is the beginning of Lunation 1185 which ends 29.97 days later with the New Moon of November on the 7th at 11:02AM EST. The Full Moon on the 24th at 12:45PM EDT is the first full moon after the “Harvest Moon” and is known as the “Hunter's Moon.” Celts called it the “Harvest Moon” and Colonial Americans called it the “Hunter's Moon” because hunting was facilitated by fields gleaned during the Harvest Moon of September, providing minimal cover for animals. Chinese refer to it as the “Kindly Moon,” and it was the “Blood Moon” in Medieval England. Anishinaabe (Odawa and Ojibwe) people recognize it as “Binaakwe-giizis” (Falling Leaves Moon.)

Lunar Perigee (closest to Earth) is 227,666 miles or 57.52 Earth radii on the 5th at 6:27PM EDT. Apogee (maximum orbital distance) occurs on the 17th at 3:16PM EDT when the Moon is at 251,175 miles (63.52 Earth radii). A 2nd perigee occurs on the 31st at 4:05PM EDT when the Moon is at a distance of 370,204 km.. It is the most distant perigee of 2018.

PlanetConstellationMagnitudeMoon PassageMoon PhaseMoon Age
SunVirgo-26.811:47PM EDT, 10/8New0 days
MercuryVirgo-1.35.5°NNE, Midnight EDT, 10/10Waxing Crescent1.01 days
VenusVirgo-4.413°N, 11;00AM EDT, 10/10Waxing Crescent1.47 days
MarsCapricornus-1.81.9°N, 9:00AM EDT, 10/18Waxing Gibbous9.38 days
JupiterLibra-1.74.0°N, 5:00PM EDT, 10/11Waxing Crescent2.72 days
SaturnSagittarius+0.41.8°N, 11:00PM EDT, 10/14Waxing Crescent5.97 days
UranusAries+5.75.0°S, 9:00AM EDT, 10/24Waxing Gibbous15.38 days
NeptuneAquarius+7.83.0°S, 6:00PM EDT, 10/20Waxing Gibbous11.76 days



  • SpectralMike, orangeusa and agmoonsolns like this


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics