July 2015 – Skies News

07/5/2015
July Skies – by Dick Cookman

Highlights: Comet Journal, Martian Landers, Meteor Showers, Pluto: Here it comes! Here it comes! There it goes…., Planet Plotting, July Moon

Focus Constellations: Cepheus, Cassiopeia, Camelopardalis, Ursa Major, Ursa Minor, Draco, Bootes, Hercules, Lyra, Aquila, Cygnus

Comet Journal

Comet C/2014 Q2 (Lovejoy) is currently at 9th magnitude and moves from Ursa Minor into Draco in July as it departs from the inner Solar System.

C/2013 US10 (Catalina) is currently at 10th magnitude and is expected to increase to 8th magnitude by the end of the month and may reach naked eye status at the end of the year. It is currently deep in southern hemisphere skies and will not be visible for northern hemisphere observers until November and December.

Mars Landers

Opportunity is on the western rim of Endeavour Crater at Marathon Valley at Spirit of St. Louis Crater. It survived the solar conjunction in mid-June when Mars was on the other side of the Sun, interrupting communication with Earth. The rover conducted limited activities during the conjunction including Alpha Particle X-ray spectroscopic investigations of some surface targets. Communication was re-established on the 19th and from the 25th through the 30th additional studies included Navigational and Panoramic camera imagery and abrasion of a rock target named Ryan NYP followed by Microscopic imagery and Alpha Particle x-ray analysis of the same target.

The Flash memory is still being bypassed due to the frequent amnesia events experienced over the last few months. Further investigation of the problem is being conducted in hopes of eventual correction. One thing we can take from the activities of the science teams since the rovers arrived on Mars is that most problems can be corrected with sufficient creativity and persistence!

Opportunity has now traversed 26.33 miles (42.37 kilometers) over the Martian surface. Solar energy in the last month has ranged between 500 and 600 watt hours per day.

In late May and June, Curiosity continued its ascent of the north flank of Mt. Sharp, the layered mountain in the center of Gale Crater, toward Logan Pass which cuts into the Washboard Unit. This is a younger rock formation immediately overlying the Murray Formation, the basal formation at Mt. Sharp, which was investigated at Pahrump Hills during the previous six months. The journey was interrupted by dune fields composed of impassable rippled soft sand on Sol 990. This caused mission scientists to alter course to a more accessible shorter route in order to reach the contact between the mudstones of the Murray Formation and the finely bedded dark sandstones of the Stimson Unit (the basal part of the Washboard Unit) in Marias Pass.

By Sol 998, Curiosity was in position to investigate the contact between the two formations. The investigation includes examination of the mineralogy, textures (grain size and shape), fabrics (grain orientation), and structures (type of layering) of the two sedimentary rock formations. The investigation was delayed due to the solar conjunction of Mars in mid-June which temporarily prevented communication with Earth, but it then proceeded apace during the rest of the month.

Initial determinations reveal a thin bed of coarser grained rock between the two formations. It contains larger grains of mixed shapes and colors, some of which are highly rounded and others quite angular. The former is indicative of distant source areas and lengthy transportation intervals and the latter suggests nearby sources. The mixture of textures and mineralogy of this unconformable boundary layer implies that the distant and surrounding landforms were subjected to an extensive period of erosion following deposition of the Murray Formation. This time interval permitted transportation of rounded material from distant sources in addition to the contributions of angular material more immediately derived from nearby elevated sources. The coarser grains found in the sandstones of the overlying Stimson Unit indicate changes in erosion and transportation processes from those during the time of formation of the mudstones of the Murray Formation.

Meteor Showers

July meteor showers are rather subdued and confined to southern skies. The pisces Austrinids on the 28th and the Alpha Capricornids on the 30th are each limited to about 5 meteors per hour in dark skies and the Delta Aquarids on the 30th may achieve as much as 20 meteors per hour. All three are competing with an almost full moon so don’t expect much.

Pluto: Here it comes! Here it comes! There it goes….

Due to the large distances involved, Pluto observations are almost impossible with telescopes of less than 12 to 14 inch diameters due to insufficient light gathering capability. However, the July 14th flyby of the probe “New Horizons” launched in January, 2006 by an Atlas V rocket will send close up views of the “dwarf” planet back to Earth from its current distance of 3.0 billion miles. If launch had been timed for arrival when Pluto was at perihelion in 1989, the distance would have been only 2.8 billion miles. Alternatively, at aphelion in the year 2113, the distance is almost 4.6 billion miles.

The best observations will be squeezed into a 2 day interval from the day before to the day after the probe zips within 6000 miles of Pluto at almost 31 thousand miles per hour. It will then proceed outward passed other Kuiper Belt objects and eventually penetrate the Oort Belt before disappearing into the depths of interstellar space.

At its current speed the probe will leave the nearby Orion Spiral Arm, traverse the Sagittarius Spiral Arm, and then pass by the center of our Milky Galaxy in about 5.8 trillion hours.

Planet Plotting

Venus and Jupiter are early evening planets in July. During the month Venus in southwestern Leo moves southeasterly away from Jupiter after their close conjunction on the 1st. Mars (+1.6 to +1.7) is on the opposite side of the Sun and is not visible from Earth in July. Saturn is visible after sunset in Libra in the southern sky and sets after midnight. Uranus and Neptune rise slightly before midnight and Mercury can be seen rising in the northeast before dawn.

Mercury brightens from magnitude -0.2 to -2.0 during the first two weeks of July as it approaches its conjunction with Mars on the 15th. It is lost in morning twilight in the last half of the month. Uranus (5.8) in Pisces, and Neptune (7.8) in Aquarius are dim morning planets that rise in the wee hours and are in the southern skies before dawn.

Venus (-4.4 to -4.7) dominates the early evening sky and outshines nearby Jupiter (-1.8 to -1.7) in Leo. On the 1st the two are less than a degree apart and by the 31st the gap increases to 6.0° as each moves farther into the glow of evening twilight and Venus draws closer to its inferior conjunction with the Sun in mid-August. Venus reaches its brightest apparition of the year at magnitude -4.7 on the 9th.

Saturn in Libra decreases slightly in brightness in July from magnitude +0.2 to +0.4 because Earth outpaces and draws away from the ringed planet as the two orbit the Sun. Saturn appears to dim and grow smaller but the tilted wide open rings remain a magnificent sight in the southern sky after sunset.

Planet……Constellation……Magnitude……Planet Passages

Sun………Gemini, Cancer….-26.8………………….New Moon, ………………………………………………………..7/15, 9:24PM EDT Mercury..Gemini, Cancer..-0.2 to -2.0 to -1.3..Mars, 0.17°NE, ………………………………………………………..7/15, 11:00PM EDT ………………………………………………………Superior Conjunction ………………………………………………………..7/23, 3:00PM EDT Venus…..Leo…………….-4.6 to -4.7 to -4.5……Jupiter, 0.4°N, ………………………………………………………..7/1, 10:00AM EDT ……………………………………………………………….Jupiter, 6.0°N, ………………………………………………………..7/31, 4:00PM EDT Mars…….Gemini………..+1.6 to +1.7……….Mercury, 0.17°SW, ………………………………………………………..7/15, 11:00PM EDT Jupiter…..Leo……………-1.8 to -1.7………………Venus, 0.4°S, ………………………………………………………..7/1, 10:00AM EDT ……………………………………………………………….Venus, 6.0°S, ………………………………………………………..7/31, 4:00PM EDT Saturn…..Libra………….+0.2 to +0.4 Uranus….Pisces……………..+5.8 Neptune..Aquarius…………+7.8

July Moon

Lunation 1144 began on June 16th with the New Moon at 10:05AM EDT. It ends 29.47 days later with the New Moon of July at 9:24PM EDT on the 15th.

Two Full Moons in July! The Full Moon of June was in Ophiuchus and the first Full Moon for July is still in Ophiuchus at 10:20 PM EDT on the 1st. This Full Moon is called the “Hay or Thunder Moon”. The 2nd Full Moon is at the end of the month on the 31st at 6:43AM EDT. It is in the constellation Sagittarius and is a “da-dingy-dong-ding / Blue Moon” if you go by the current definition that “Blue Moons” are the 2nd Full Moon in a month. An older definition states that “Blue Moons” are the 3rd Full Moon in a season with 4 Full Moons. In that case there are no “Blue Moons” in 2015. The term “Blue Moon” can also refer to the bluish color of the Moon when its light is influenced by volcanic dust in the atmosphere.

The 1st Full Moon is the 7th Moon of the year which is designated by the eastern Anishinaabe (Odawa and Ojibwe) of the northern Great Lakes as “Miin-giizis” (Berry Moon). The western Anishinaabe call it “Aabitaa-niibino-giizis” (Halfway Summer Moon) and Colonial Americans followed their lead and called it the “Summer Moon”. The 2nd Full Moon is the 8th Moon of the year and is the Anishinaabe “Manoominike-giizis” (Ricing Moon). Celts called the first Full Moon the “Moon of Claiming” and Medieval English referred to it as the “Mead Moon.” Chinese call it the “Hungry Ghost Moon”.

The Moon is nearest (perigee) in its orbit (228,101 miles or 57.55 Earth radii) on July 5th at 2:52PM EDT. Apogee distance (maximum distance) is 251,553 miles (63.47 Earth radii) from Earth on the 21st at 7:02PM EDT.

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

Sun……..Gemini……-26.8………9:24PM EDT, 7/15 ………………………………………………………………New ~ 0 days Mercury..Gemini……+1.4……….5.5°S, 1AM EDT, 7/15 …………………………………………Waning Crescent ~ 28.62 days Venus…..Leo…………-4.7………….0.4°S, 9PM EDT, 7/18 …………………………………………Waxing Crescent ~ 2.69 days Mars…….Gemini…….-1.6…………5.8°S, 4AM EDT, 7/15 …………………………………………Waning Crescent ~ 28.75 days Jupiter….Leo………….-1.7………….4.0°S, 2PM EDT, 7/18 …………………………………………Waxing Crescent ~ 2.98 days Saturn….Libra………..+0.4………….2.0°N, 4AM EDT, 7/26 …………………………………………Waxing Gibbous ~ 10.28 days Uranus….Pisces……..+5.8………….0.8°S, 11PM EDT, 7/8 …………………………………………Waning Gibbous ~ 22.54 days Neptune..Aquarius….+7.8…………3.0°N, 4AM EDT, 7/6 …………………………………………Waning Gibbous ~ 19.75 days