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May 2019 Skies

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May Skies

by Dick Cookman


Highlights: Comet Journal, Martian Landers, Meteor Showers, Planet Plotting, May Moon

Focus Constellations: Auriga, Gemini, Cancer, Leo, Leo Minor, Coma Berenices, Virgo, Bootes, Corona Borealis, Hercules, Draco, Cepheus, Cassiopeia, Camelopardalis, Lynx, Ursa Major, Ursa Minor

Comet Journals

C/2018 Y1 (Iwamoto) is an evening comet at 12th magnitude in Perseus which sets after 10:00PM EDT on the 1st and before 9:00PM EDT on May 31. It will move eastward until July after which it will move north northwestward through Perseus as it exits the inner solar system and returns to its aphelion between the Oort Cloud (10000+ AU’s) and Kuiper Belt (30 - 50 AU’s), the normal homes for longer period comets. No other comet is brighter than 13th magnitude in May.

Mars Landers

Opportunity's mission is complete as of Sols 5347 to 5353 (Feb. 7, 2019 - Feb. 13, 2019). No response has been received from Opportunity since Sol 5111 (June 10, 2018,) due to a planet-encircling dust storm on Mars. With the last uplink transmission on Sol 5352 (Feb. 12, 2019), the rover recovery efforts are concluded. Total odometry on Mars for the rover was 28.06 miles (45.16 kilometers).

The InSight lander arrived on Elysium Planitia on Mars on Nov. 26, 2018. It immediately unfurled its solar panels and radio antenna and successfully deployed its seismometer on the Martian surface by December 19. The mole carrying the Heat Flow and Physical Properties Package (HP3) instrument burrowed 30 cm. into the ground for the first time on Feb. 28 with its hammer drill and encountered a zone through which it could not penetrate. German scientists who designed the mole are now conducting a series of tests on Earth which are designed to evaluate and solve the drilling problem. Measurements of conditions during the drilling include temperature data, visual images, and seismic data recorded during hammering provided a basis for designing the tests which include the possibilities that the mole may have encountered a large rock through which it was unable to drill, or the Mars sand may be more cohesive than expected causing hammering induced cavities to form around the mole, allowing it to shift sideways instead of drilling downwards. Despite the drilling difficulties, InSight is actively continuing with other measurements. These include surface weather conditions, magnetic field measurements, and detection of small seismic events on March 14, April 10, April 11, and a larger event on April 6 that may represent a likely “marsquake.”

The Curiosity Rover is investigating 16,404 foot Mt. Sharp at Gale Crater’s center in its search for evidence of pre-existing life on Mars. Curiosity is within Glen Torridon the clay-bearing unit adjacent to Vera Rubin Ridge which was the target of investigation of the rovers activities even before the spacecraft was launched because it may hold more clues about the ancient lakes that helped form the lower levels on Mt. Sharp. Curiosity drilled a piece of bedrock nicknamed Aberlady on Saturday, April 6 (Sol 2,370), and delivered the sample to its internal mineralogy lab on Wednesday, April 10 (Sol 2374).

The rock was easily drilled by the rover in contrast to harder rocks drilled earlier on Vera Rubin Ridge. The drill didn't even use its percussive technique. This was the mission's first sample obtained using only rotation of the drill bit.

"Curiosity has been on the road for nearly seven years," said Curiosity Project Manager Jim Erickson of NASA's Jet Propulsion Laboratory in Pasadena, California. "Finally drilling at the clay-bearing unit is a major milestone in our journey up Mount Sharp."

Clay minerals are tempting targets for analysis because they usually form in water. NASA's Mars Reconnaissance Orbiter (MRO) spied a strong clay "signal" here long before Curiosity landed in 2012 and discovery of the signal’s source could determine if a wetter Martian era shaped this layer of Mount Sharp, the 3-mile-tall (5-kilometer-tall) mountain.

Clay minerals in mudstones were found before in many places on Mars. The mudstones formed as rivers entered ancient lakes nearly 3.5 billion years ago and deposited their sediment load. As with water elsewhere on Mars, the lakes eventually dried up, and the buried sediment was compacted into mudstone.

The region clearly has several other clues to reveal. There are several kinds of bedrock and sand, including active sand ripples that have shifted in the past year. Pebbles are scattered everywhere - are they eroding from the local bedrock? Several eye-catching landmarks, such as Knockfarril Hill, stick out as well.

"Each layer of this mountain is a puzzle piece," said Curiosity Project Scientist Ashwin Vasavada of JPL. "They each hold clues to a different era in Martian history. We're excited to see what this first sample tells us about the ancient environment, especially about water."

The Aberlady sample will give the team a starting point for investigation of the clay-bearing unit. Mission scientists plan to drill into the unit several more times over the course of the next year. That will help them understand what makes this region different from Vera Rubin Ridge behind it and an area higher on the mountain in which the NASA Mars Reconnaissance Orbiter (MRO) detected a sulfate signal.

Meteor Showers

In early May, dark New Moon skies unpolluted by unshielded outdoor lighting offer two Meteor Showers:

Early May, June, and July: Sagittarids. Peak 22hr 30min UT Active Apr 15-Jul 15. Radiant 16h28m -22°. ZHR ~5. 30 km/sec. just before and after New Moon.

May 6: Eta Aquarids Active Apr 19-May 28. Radiant 22h32m -01°. ZHR ~40. 66 km/sec. 1 day after New Moon. Progenitor: Comet 1P/Halley

Planet Plotting

May morning skies reward early risers with Jupiter (-2.2 to -2.4) in Ophiuchus, Saturn (+0.5 to +0.3) in Sagittarius, Venus (-3.8) in Pisces and Aries, Uranus (+5.9) in Aries, and Neptune (+7.9) in Aquarius. The planets appear in the southeastern sky with Jupiter rising before midnight EDT in early May, followed by Saturn about 2 hours later, and the last three rise in the twilit skies of dawn. At the beginning of the month, Mercury (+0.2) in Pisces may be visible north of Venus right above the horizon. Both will sink deeper into the glow of sunrise during May as Neptune moves higher in the dawn sky.

Mars (+1.5 to +1.6) in Taurus and Mercury (+0.2 to -2.2 to -1.1) in Pisces, Aries, and Taurus, are evening planets in May. Mars is low in the early evening western sky and sets before 11:00PM EDT on the 1st and about 10pm EDT on the 31st. Mercury will not appear in the western sky until very late in May after its conjunction with the Sun on the 21st.

The waning crescent Moon is 4° from Venus at 8AM EDT on the 2nd, 3° from Mercury at 2:00AM EDT on the 3rd, 4° from Neptune at 1:00PM EDT on the 27th, and 5.9° from Uranus at 6:00AM EDT on the 31st. Its waxing crescent is 3° from Mars at 8:00PM EDT on the 7th and a waning gibbous Moon is 1.7° from Jupiter at 1:00PM EDT on the 20th and 0.5° from Saturn at 6:00PM EDT on the 22nd

PlanetConstellation(s)MagnitudePlanet PassagesTime, Date
SunAquarius, Taurus-26.8New Moon4:50AM EDT, 5/4
MercuryPisces, Aries, Taurus+0.2 to -2.2 to +1.1Uranus, 1.26°NNW
Superior Conjunction
Noon EDT, 5/8
9:00AM EDT, 5/21
VenusPisces, Aries-3.8Uranus, 1.2°N4:00AM EDT, 5/18
MarsTaurus, Gemini+1.6 to +1.8  
JupiterOphiuchus-2.2 to -2.4  
SaturnSagittarius+0.5 to +0.3  
UranusAries+5.9Mercury, 1.26°SSE
Venus, 1.2°S
Noon EDT, 5/8
4:00AM EDT, 5/18

May Moon

May’s New Moon is on the 5th at 4:50AM EDT. It is the beginning of Lunation 1192 which ends 29.47 days later with the New Moon of June on the 3rd at 6:02AM EDT.

The Full Moon on the 18th at 5:11PM EDT. The May Moon is known as the “Planting or Milk Moon”. Colonial Americans called the May Moon the “Milk Moon” and Celts called it the “Bright Moon”. It was named the “Hare Moon” in Medieval England. Chinese refer to it as the “Dragon Moon” and the Anishinaabe (Odawa and Ojibwe) people recognize it as “Zaagibagaa-giizis” (Budding Moon.)

Lunar Perigee (minimum orbital distance) is on the 13th at 5:53PM EDT when the Moon is at a distance of 229,291 miles. (57.86 Earth radii). Apogee occurs on the 26th at 9:27AM EDT when the Moon is at 251,119 miles (63.36 Earth radii).

PlanetConstellationMagnitudeMoon PassagesMoon Phase, Moon Age
SunAries-26.86:46PM EDT, 5/4New, 0 days
MercuryPisces-0.43.0°S, 2:00AM EDT, 5/3Waning Crescent, 27.62 days
VenusPisces-3.84.0°S, 8:00AM EDT, 5/2Waning Crescent, 27.13 days
MarsTaurus+1.73.0°S, 8:00PM EDT, 5/7Waxing Crescent, 2.34 days
JupiterOphiuchus-2.41.7°N, 1:00PM EDT, 5/20Waning Gibbous, 15.47 days
SaturnSagittarius+0.30.5°S, 6:00PM EDT, 5/22Waning Gibbous, 17.63 days
UranusAries+5.95.9°S, 6:00AM EDT, 5/31Waning Crescent, 26.59 days
NeptuneAquarius+7.94.0°S, 1:00PM EDT, 5/27Waning Crescent, 22.38 days


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