October 2015 – Skies News

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

Comet Journal

Comets in October are dim. There are no northern hemisphere comets brighter than 10th magnitude. We will have to wait until early November when C/2013 US10 (Catalina) may burst into predawn skies between Libra and Virgo and be visible to the naked eye. It is now at 6th magnitude but is still buried deeply in southern hemisphere skies. It will peak at magnitude 4 in the latter part of November and remain bright in December and January. 10th magnitude C/2014 S2 (PanSTARRS) and 22P/Kopff (2015) are between Scorpius and Ophiuchus and in Ursa Minor respectively.

Comet C/2014 Q2 (Lovejoy) is currently at 11th magnitude and is between northern Bootes and Hercules in October. It is rapidly receding northward in space toward the Oort Belt.

Mars Landers

Opportunity is in Marathon Valley searching for the phyllosilicate clay minerals which were discovered via satellite spectral studies. On Sol 4114 (Aug. 20, 2015), the rover drilled about 2.5 millimeters into the surface of a target called “Pvt. Robert Frazer” using the Rock Abrasion Tool (RAT) on the end of the robotic arm but could not brush the freshly exposed surface due to a sequencing error. Meanwhile, Opportunity proceeded with remote sensing of Marathon Valley with several Panoramic Camera (Pancam) panoramas collected of the north wall of the valley plus some 13-filter Pancam images of selected surface targets. An Alpha Particle X-ray Spectrometer APXS measurement of atmospheric argon was collected on the evening of Sol 4116 (Aug. 22, 2015).

After completing brushing and testing of the outcrop and conducting more remote sensing, the rover drove to the west about 46 feet (14 meters) on Sol 4125 (Sept. 1, 2015) in order to approach a new geological contact. After conducting detailed observations of the surface targets, Pvts. “Silas Goodrich and George Gibson,” Opportunity was configured from RAM-only operation to the Flash memory as a planned test of the non-volatile storage system. The drive on that sol completed successfully, but an amnesia event with Flash prevented a return of drive-related data on that sol. Those data are expected to be received on subsequent sols. Plans are to continue to operate in Flash for one week in order to gain information and statistics on the state of the malfunctioning Flash storage system.

Opportunity has now traversed 26.43 miles (42.53 kilometers) over the Martian surface. Solar energy in the last month ranged from 335 to 405 watt hours per day.

Curiosity departed Marias Pass on August 12th and is climbing Mt. Sharp on a southwesterly course after spending the last few weeks investigating the contact zone below the finely bedded dark sandstones of the Stimson Unit, the base of the Washboard Unit, and the light colored mudstone of the Murray Formation, the basal formation at Mt. Sharp. The rover is examining the high silica hydrogen rich samples obtained by drilling the target called “Buckskin” near the contact zone as it travels.

The dark sandstone of the Washboard Unit over which the rover was traveling as of September 11th displays large scale cross-bedding typical of windblown sand deposited as dunes on Earth. The mudstones of the underlying Murray Formation are more typical of a lake bottom depositional environment indicating that there was a significant drop in lake level during the time of transition represented by the contact zone.

Water on Mars? Life?

The recent reports of liquid water on Mars from NASA are based on spectral measurement of seasonal dark streaks on the planet’s surface. The measurements reveal the presence of chemicals capable of extracting water from the atmosphere through a process called deliquescence. The chemicals limit evaporation or boiling of water and lower the freezing temperature of the liquid saline water to -10°F permitting it to flow over the surface.

When Curiosity was back in Yellowknife Bay, it took pictures of a rock outcrop called Gillespie Lake which was formed from sediments deposited as an ancient lakebed. The images were analyzed by Nora Noffke, a geobiologist at Old Dominion University in Virginia whose expertise is in microbially induced sedimentary structures (MISS). She has 20 years of research experience devoted to microbial structures and last year reported discovery of 3.48 billion year old MISS in western Australia’s Dresser Formation – potentially evidence for the oldest signs of life on Earth. Her analysis of the Gillespie Lake images revealed structures very similar to the MISS found on Earth, but confirmation requires analysis of collected samples and the rover is a long way from Yellowknife Bay.

The water and the MISS evidence mentioned above, along with measurements of sporadic atmospheric methane and the organic molecules found in drilling samples from Gale Crater on Mars provide evidence that Mars may have have been a living world long ago and that some forms of life may survive to this day.

Meteor Showers

The Draconid and Orionid Meteor Showers are the best of October. The former is well timed as it occurs during the waning Moon phase on the night of October 8/9. The shower is exceptionally variable, ranging from a few meteors per hour to more than 500. Meteor storms occurring in 1933, 1946, and 2011 produced 300 per hour in dark sky locales. The debris shower from Comet 21P/Giacobini-Zinner is not expected to produce anything approaching these rates, but you never know……

The Orionids on the night of October 21/22 are facing more competition from waxing gibbous Moon but predawn observers may see a pretty good show after moonset. Debris from Comet 1P/Halley fuels the meteor shower which ranges from 5 to 70 meteors per hour. Astronomers expect values closer to the former this month.

Planet Plotting

Saturn (+0.5 to +0.6) in Scorpius is an evening planet throughout October. It is above the southwestern horizon after sunset and does not set until 2 hours after sunset in mid-October. Neptune (+7.8) in Aquarius rises well before sunset and sets before dawn. Uranus (+5.7) in Pisces sets 2.5 hours after Neptune.

The morning planets are Venus (-4.7 to -4.5), Jupiter (-1.7 to -1.8), Mars (+1.8 to +1.7), and Mercury (+0.3 to -1.0).
Mercury in Virgo is closest to the Sun in early October and reaches maximum western elongation in Virgo on the 15th after which it will get brighter but will drop deeper into the glow of the rising Sun.

During the 1st half of the month, Mars will rise before Jupiter in Leo and will appear to pass within 1 degree of the giant planet on the 17th. In the latter part of the month, it will rise in Leo after Jupiter.

Venus in Leo is highest of the four in the eastern predawn sky on the 1st and appears to pass Jupiter on the 26th. They will be within 5 degrees of one another during the last third of October presenting an awe-inspiring apparition of the two brightest planets for early rising observers. On the 28th, Mars will join the party when it appears to approach the spectacular pair.

Planet……Constellation……Magnitude……Planet Passages

Sun………..Virgo…………-26.8………………….New Moon, ………………………………………………………..10/12, 8:06PM EDT Mercury…..Virgo…………+0.3 to -1.0…….Max West Elongation ……………………………………………………….10/15, 11:00PM EDT Venus….Cancer, Leo……-4.7 to -4.5…….Max West Elongation ………………………………………………………..10/26, 3:00AM EDT ………………………………………………………..Jupiter, 1.1°N, ………………………………………………………..10/26, 4:00AM EDT
Mars………Leo…………….+1.8 to +1.7…….Jupiter, 0.4°S, ………………………………………………………10/17, 10:00AM EDT
Jupiter……Leo…………………..-1.7…………..Mars, 0.4°N, ………………………………………………………10/17, 10:00AM EDT ………………………………………………………..Venus, 1.1°S, ………………………………………………………..10/26, 4:00AM EDT
Saturn……Scorpius……….+0.6 to +0.5 Uranus…….Pisces………………+5.7………….Opposition ………………………………………………………10/21, Midnight EDT
Neptune…Aquarius………+7.8

October Moon

Lunation 1148 begins with the New Moon of October 12th at 8:06PM EDT. It ends 29.73 days later with the New Moon of November 11th at 12:47PM EDT.

The Full Moon for October in Pisces at 8:05AM EDT on the 27th is another “Supermoon”. It is the “Hunter’s Moon” because it is the Full Moon following the “Harvest Moon” of September.

The Full Moon is the 11th Moon of the year due to two Full Moons in July and is designated by the Anishinaabe (Odawa and Ojibwe) of the northern Great Lakes as “Gashkadino-Giizis or Baashkaakodin-Giizis” (Freezing Over Moon). Celts called the October Full Moon the “Harvest Moon” and Medieval English referred to it as the “Blood Moon.” It is the “Kindly Moon” for the Chinese and Colonial Americans called it the “Hunter’s Moon” because its light allowed hunters to hunt in the stubble of the crops harvested in September.

Apogee distance (maximum orbital distance) is 252,518 miles (63.73 Earth radii) from Earth on the 11th at 9:18AM EDT. Perigee distance is 221,739 miles or 55.95 Earth radii on October 26th at 9:01AM EDT, slightly less than 24 hours before Full Moon. The proximity of the October Full Moon provides us with the “Supermoon”. The 24 hours from perigee to Full Moon is twice as long as the 12 hour difference in October so the Full Moon will be slightly smaller than the “Supermoon” of September.

Planet..Constellation..Magnitude..Moon Passage..Moon ………………………………………………………………….Phase/Age

Sun………Virgo…….-26.8…………………..8:06PM EDT, 10/12 ………………………………………………………………New ~ 0 days Mercury…Virgo…….+0.3…………..0.9°S, 8AM EDT, 10/11 …………………………………………Waxing Crescent ~ 28.82 days Venus……Leo……….-4.6…………0.7°S, 5PM EDT, 10/8 …………………………………………Waning Crescent ~ 25.60 days Mars……..Leo……….+1.8…………3.0°S, 1PM EDT, 10/9 …………………………………………Waning Crescent ~ 26.68 days Jupiter……Leo………-1.7…………3.0°S, 8PM EDT, 10/9 …………………………………………Waning Crescent ~ 26.72 days Saturn….Scorpius….+0.6………….3.0°N, 9AM EDT, 10/16 …………………………………………Waxing Crescent ~ 3.54 days Uranus….Pisces…….+5.7………….0.9°S, 6AM EDT, 10/26 …………………………………………Waxing Gibbous ~ 13.41 days
Neptune..Aquarius…+7.8…………3.0°N, 3PM EDT, 10/26 …………………………………………Waxing Gibbous ~ 10.79 days