June 2015 – Skies News

06/6/2015
June Skies – by Dick Cookman

Highlights: Comet Journal, Martian Landers, Meteor Showers, Summer Solstice, Planet Plotting, June Moon

Focus Constellations: Cepheus, Cassiopeia, Camelopardalis, Lynx, Leo, Coma Berenices, Bootes, Hercules, Draco, Ursa Major, Ursa Minor

Comet Journal

After achieving 4th magnitude at the end of 2014, Comet C/2014 Q2 (Lovejoy) passed by Polaris in Ursa Minor at the beginning of June and will continue southward though the Little Dipper during the month. It is currently at 8th magnitude and will decrease to 9th magnitude in July as it departs from the inner Solar System.

C/2013 US10 (Catalina) is currently at 11th magnitude and is progressing on its extended climb to potential naked eye status at the end of the year. It is now well below the plane of the Solar System and will rise into northern hemisphere skies at the end of 2015. This is the first time that it has visited the inner Solar System and gravitational interaction with its members is expected to alter the orbit of the comet. It may actually achieve escape velocity as the Sun and other planets fling it away from the Solar System on an unending hyperbolic orbit, never to return. Maybe we could hitch a ride and embark on the 1st interstellar journey in human history!

C/2014 Q1 (PanSTARRS) will be in northern hemisphere skies in June and most of July. It will depart from Aries, pass through Taurus, and move into Auriga in June. It is currently at 10th magnitude but will brighten and may be visible to naked eyes in early July when it could reach 3rd or 4th magnitude near its close approach to the Sun (perihelion).

Mars Landers

After master sequence control was established on Sol 3996 (April 21, 2015) following the latest reset and amnesia event, Opportunity drove 26 feet on Sol 3998 (April 23, 2015) to reach the rock outcrops at Spirit of St. Louis Crater along the western rim of Endeavour Crater at Marathon Valley. After traveling another 16 feet on Sol 4000, the rover started investigating an outcrop called Lambert Field. The investigation was interrupted by another benign amnesia event on Sol 4002 after which Opportunity took another 30 foot drive into the crater to the central peak dubbed Lindbergh Mound where it performed some (contact) science at a target called Roosevelt Field.

Between Sol 4002 and Sol 4027 the rover examined a number of rock outcrops within the crater and experienced three amnesia events and two resets. These difficulties led project leaders to configure the rover in RAM-only mode on Sol 4027 (May 23, 2015) in order to avoid the use of non-volatile Flash memory for storage. On Sol 4029 -4031 (May 25 – 27, 2015), Opportunity successfully completed a 157-foot drive and a 60 foot drive, putting the rover outside of the Spirit of St. Louis crater. In this location the rover can observe nearby outcrops during the Solar Conjunction when it will be out of contact with Earth. 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.

On April 16th Curiosity passed the 10 kilometer mark on Mars as it continued its ascent up the north flank of Mt. Sharp, the layered mountain in the center of Gale Crater. The previous six month investigation of the the mountain’s basal (oldest) rock unit called the Murray Formation at Pahrump Hills revealed a sequence of rock layers reflecting a specific sequence of changing environmental conditions. The oldest rocks include clay rich minerals, at Confidence Hills, which were probably formed in a wet environment with moderate temperatures and pH levels. The next oldest, at Mojave, contain jarosite (calcium & sulfur) formed in acidic, oxidizing conditions. The youngest at Telegraph Peak, have quartz (silicon & oxygen) and cristobalite (silicon, oxygen, and water) minerals which, on Earth, can be associated with crystallization from hydrothermal fluids moving upward from deep sources.

Curiosity is heading upward toward Logan Pass which cuts into the Washboard Unit, the next youngest rock formation overlying the Murray Formation. It is composed of high buttes which produce a corrugated appearance from above. Similar corrugated patterns have been mapped from orbit at many locations surrounding Mt. Sharp and probably represent exposures of the same formation.

The Chemcam (chemistry & camera) instrument onboard Curiosity initially utilized a laser rangefinding focuser to auto-focus the main laser. This component zapped the specimen and analyzed the resulting spectrum to determine chemical composition. The focuser failed quite some time ago forcing scientists to zap specimens multiple times and sending the information back to Earth to determine which one had the proper focus and provided the correct analysis. The Chemcam instrument has now been improved upon on the fly when new software was sent and installed. The new software automated the process by autonomously selecting which of the multiple images and analyses should be sent back to Earth. Mission scientists are convinced that the new setup is actually an improvement on the initial setup because it has produced better quality images and analyses.

Meteor Showers

Comet 7P Pons-Winneke visited the inner Solar System and passed through perihelion when it was closest to the Sun in January of this year. The comet is now returning to its aphelion near Jupiter’s orbit. It circuits the Sun every 6.37 years and has formed a river of debris along its orbit during its many passages through our neighborhood. Earth passes through this debris in mid-June and will be in the densest region on the mornings of the 24th and 25th when meteors will radiate outward from Bootes and Draco in the northwestern sky. According to Guy Ottewell in his 2015 Astronomy Calendar, the meteor shower has produced as many as 100 meteors per hour in dark skies during years when the comet was at or near perihelion such as in 1998 and 2004. The combination of timing during 1st Quarter Moon and the recent January perihelion for the comet provides an auspicious outlook for a very good meteor shower. Clear Skies!

Summer Solstice

The Solstice occurs at 12:38PM on the 21st. Earth is positioned in its orbit so that its axis is tilted at 23.4° toward the Sun exposing the northern hemisphere to more direct solar radiation. At latitude 45° north, the Sun will be 68.5° above the south point on the horizon at Solar noon, its highest elevation of the year. This results in the longest day and shortest night. The earliest sunrise (4:31AM EDT) occurs a week earlier on the 14th and the latest sunset is a week later on the 28th.

Planet Plotting

Venus and Jupiter are early evening planets in June. Venus moves from Gemini to Cancer and into Leo in June and Jupiter is in Leo throughout the month. Mars (+1.5 to +1.6) is on the opposite side of the Sun and is not visible in June from Earth. Saturn is visible for most of the night in Scorpius while Mercury, Uranus and Neptune are early morning planets.

Mercury (+2.6 to -0.1) was at inferior conjunction with the Sun on May 30th and isn’t visible in the morning sky until appearing in the glow of sunrise in Taurus on the 22nd. It will be within 2.0° of Aldebaran on the 24th. Uranus (5.9) in Pisces, and Neptune (7.9) in Aquarius are dim morning planets that rise in the wee hours and are in the southern skies before dawn.

Venus (-4.4 to -4.6) dominates the early evening sky and outshines nearby Jupiter (-1.9 to -1.8) in Leo by 10 to 15 times in June. On the 19th and 20th the two will be joined by the crescent Moon and on the 30th the planets will be within 0.3° of of one another, producing spectacular evening apparitions.

Saturn (+0.1 to +0.2) in Scorpius is next to the gibbous Moon on the 1st and the 28th. It was closest to Earth and at its brightest at opposition on May 22nd, but will remain close throughout June providing magnificent views of wide open rings.

Planet……Constellation……Magnitude……Planet Passages

Sun………Taurus, Gemini………-26.8………New Moon, ………………………………………………………..6/16, 10:05AM EDT Mercury..Taurus……………+2.6 to -0.1..Max. West Elongation, ………………………………………………………..6/24, 1:00PM EDT Venus.Gemini/Taurus/Leo.-4.4 to -4.6.Max. East Elongation, ………………………………………………………..6/6, 2:00PM EDT ……………………………………………………..Jupiter, 0.3°SW, ………………………………………………………..6/30, 11:00PM EDT Mars…….Taurus……………+1.5 to +1.6..Solar Conjunction, ………………………………………………………..6/14, Noon EDT Jupiter…..Leo……………….-1.9 to -1.8…….Venus, 0.3°NE, ………………………………………………………..6/30, 11:00PM EDT Saturn…..Scorpius…………+0.1 to +0.2 Uranus….Pisces…………….+5.9 Neptune..Aquarius…………+7.9

June Moon

Lunation 1143 started with the New Moon of May at 12:13AM EDT on the 18th. It will end 29.41 days later with the New Moon of June at 10:05AM EDT on the 16th.

June’s Full Moon is in Ophiuchus is at 12:19PM EDT on the 2nd when the Earth and Ophiuchus are on opposite sides of the Moon. Ophiuchus is actually the 13th constellation of the Zodiac but is not recognized as such in western culture. Instead, its place is partitioned between Scorpius and Sagittarius. At the beginning of the year, Ophiuchus and the Earth are on opposite sides of the Sun, so the Sun is in Ophiuchus. Native Americans observed that the Moon and Sun moved through 13 constellations during the year and based their calendar on the 13 “Moons”. Anishnaabe (Odawa and Ojibwe) of the northern Great Lakes call the 6th Moon of the year “Ode’imini-giizis” (Strawberry Moon). Some people have adopted the Anishnaabe term and others call the June Moon the “Flower Moon” or use the Colonial American name (Rose Moon). Celts called it the “Moon of Horses” and Medieval English referred to it as the “Dyan Moon.” Chinese call it the “Lotus Moon”.

Apogee distance (maximum distance) is 251,116 miles (63.36 Earth radii) from Earth on the 23rd at 1PM EDT. The Moon is nearest (perigee) in its orbit (229,728 miles or 57.97 Earth radii) on June 10th at 12:44AM EDT.

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

Sun…….Taurus………-26.8………10.05AM EDT, 6/16 ………………………………………………………………New ~ 0 days Mercury..Taurus…….+1.7…………0.04°S, 10PM EDT, 6/14 …………………………………………Waning Crescent ~ 27.91 days Venus…..Cancer…….-4.6………….6.0°S, 7AM EDT, 6/20 …………………………………………Waxing Crescent ~ 3.87 days Mars…….Taurus…….-1.5…………4.7°SSE, 9AM EDT, 6/16 …………………………………………Waning Crescent ~ 29.37 days Jupiter….Leo…………-1.8………….5.0°S, 8PM EDT, 6/20 …………………………………………Waxing Crescent ~ 4.41 days Saturn….Scorpius…..+0.1………….1.9°N, 4PM EDT, 6/1 …………………………………………Waxing Gibbous ~ 14.66 days Saturn….Scorpius…..+0.2………….2.0°N, 9PM EDT, 6/28 …………………………………………Waxing Gibbous ~ 14.45 days Uranus….Pisces……..+5.9………….0.5°S, 4PM EDT, 6/11 …………………………………………Waning Gibbous ~ 24.66 days Neptune..Aquarius….+7.9…………3.0°N, 11PM EDT, 6/8 …………………………………………Waning Gibbous ~ 21.87 days