StarWatch for the greater Lehigh Valley
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SEPTEMBER  2018

SEPTEMBER STAR MAP | MOON PHASE CALENDAR | STARWATCH INDEX | NIGHT SKY NOTEBOOK

Print Large Sky Charts For 10 p.m. EDT:   NORTH | EAST | SOUTH | WEST | ZENITH

[Moon Phases]
 
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1150    SEPTEMBER 2, 2018:   Moravian’s Robotic Observatory Online
Somehow five people managed to get through a week starting August 1 at the Mars Desert Research Station with under 300 gallons of water. About one third of that amount was used to run the swamp box for about three hours each day to cool down the habitat to a tolerable temperature. Every day, except for one of the eight that we were at MDRS, the out-of-doors temperature reached into the low 100’s. There was also no refrigeration, and we were without electricity for the first night, forcing us to sleep outside. Why would anyone want to live in such a hostile environment? It’s really quite tame compared to Mars, where heat is substituted for bone-chilling cold, and all exterior work must be conducted within the confines of a pressurized spacesuit. And yes, we went into town, Hanksville, Utah, population 202, each day for a meal or a milkshake. When you think about it in that respect, our habitat and environs were more than habitable. Still, most people avoid living in such an environment. Because of this, the Hanksville area is one of the darkest locations in the continental US to conduct astronomical research, and it is here that Moravian College has staked its claim in time-sharing with the Mars Society to build the MDRS Robotic Observatory. When the idea was first pitched in 2016, we gave it about a 5-10 percent chance of success; yet here we were, Peter Detterline, Jacob Wetzel, Adam Jones, Adam Biel, and I putting the finishing touches on a dream come true. Pete, Jacob, and Adam Jones are all former students of mine, but it has been Peter Detterline that has been the driving force behind the project. Although Moravian has a 25 percent share of telescope time, no Moravian funds were allocated by the College for its construction. Our $20,000 share was raised solely through public donations, about half coming from the generous contributions of Dr. Carlson R. Chambliss, who was Pete’s and my astronomy professor when we attended Kutztown University back in the 1970s. In fact, it was Moravian’s contribution that supplemented the original funding provided by an anonymous donor from the Mars Society to make the observatory fully robotic. During our week at MDRS we cleaned all components and made some minor mechanical repairs to the dome. Pete put the observatory through its paces, operating it remotely from the habitat in a similar fashion to how individuals from Moravian College and worldwide participants will use it. The only difference was when glitches occurred we were on site immediately to correct the problem. We also installed two weather stations to act as backup units to the main Boltwood sensor which gives the electronic permission for the clamshell observatory dome to open if weather conditions are suitable for astronomical viewing. The Boltwood closed the dome automatically one evening when the wind picked up during the passage of a nearby thunderstorm. On our return trip back East to Pennsylvania, Pete operated the facility from our hotel room, gathering data for the new online course on astronomy research that he is currently teaching at Moravian. You can get a live look at the MDRS Robotic Observatory by downloading the BloomSky Weather application onto your smart phone. David Fisherowski of Boyertown, a major donor of astronomical equipment to Moravian College Astronomy, provided the unit. It has a fisheye camera so that every Hound can keep an eye on the facility. Once the BloomSky program loads, perform a search for MDRS Hanksville, Utah or use the “Explore” tab at the bottom of the screen to scroll across the US to Utah. The BloomSky positioned most centrally in the state is the one looking at the MDRS Robotic Observatory. When you see the temperature icon for Moravian’s site, tap on it. When the MDRS site loads, tap on the “Star” icon so that you can “favor” it and automatically go to the site whenever the application is loaded. Daily weather loops can be found on YouTube at Moravian College Wx1. Approximately 55 Moravian students including Dr. Kelly Krieble and Dr. Ruth Malenda will have the opportunity of using the facility during the fall term.
 

1151    SEPTEMBER 9, 2018:   Record Misery for Late Summer
Let’s talk about the “fantastic” weather that the East Coast has been experiencing during the past week because we sure aren’t going to see many stars during this week. I’ll take the clearer, drier, 100-degree plus weather of the Southwest any day of the week over the 90-degree weather with high relative humidities and dew points like we have experienced lately. Relative humidity, expressed as a percentage, is the ratio of the amount of moisture in the air compared to the maximum amount of moisture that can be present in the atmosphere at that temperature. The dew point is the temperature at which a given parcel of air will achieve a relative humidity of 100 percent. Expressed in another way, the dew point is the temperature to which the air needs to be cooled in order to become completely saturated with moisture. If the air were cooled even more, water vapor would condense out of the atmosphere, generally as fog or precipitation. The highest dew point recorded was 95 degrees F. at Dhahran in eastern Saudi Arabia on July 8, 2003. With an air temperature of 108 degrees F., it felt like the temperature (heat index) was 178 degrees F. (World Meteorological Organization). Dhahran is just north of the island nation of Bahrain on the Persian Gulf. As noted above, when the dew point and air temperature are high, it can feel downright insufferable. A more realistic example, similar to what we experienced on several days this past week, was an air temperature near 95 degrees F. with a humidity of 55 percent, creating a dew point about 75 degrees F. Compare that to a day last month when I was at the Mars Desert Research Station near Hanksville, UT where Moravian has its timeshare in the MDRS Robotic Observatory. The temperature climbed to nearly 105 degrees F., on one day but with a relative humidity of only 15 percent. The dew point was a mere 45 degrees F. If consideration is given to the heat index which factors humidity into the equation to gain a better approximation of how the air temperature feels, it was still 105 degrees F. at MDRS; however, the heat index on the near 95-degree days back East was also about 105 degrees F. So was it blistering hot when I went out-of-doors at MDRS? You bet, but at least when I sweated the low humidity caused efficient evaporation which acted to cool me more quickly instead of dripping sweat as I often do back East. A low humidity environment is also much more conducive for making good astronomical observations. Weather conditions are generally clearer and the sky more transparent because it is more difficult to attain the dew point to form clouds. It is even more difficult to reach the dew point near the surface where the ground has been warmed greatly by the sun during the daytime. Thus worrying about moisture collecting on the optics of a telescope and other equipment exposed to the nighttime air becomes a nonissue. That is not the case in the eastern half of the country where dew shields and heaters on telescopes have to be employed to prevent condensation from occurring on the instrumentation. On that 105-degree Utah day where the humidity was only 15 percent, the temperature of the equipment would have to drop to 45 degrees F. during the night before dewing would occur. Although diurnal temperatures are much greater in dry climates than in humid regions, a difference of 60 degrees F. between day and night is just not likely to happen, even in the desert Southwest.
 

1152    SEPTEMBER 16, 2018:   The Universe is a Grand Illusion
If you could look at the universe from far, far away, it would appear homogeneous, pretty much the same in all areas, but as you came closer, irregularities would begin to appear. The cosmos would become sponge-like with vast, dominating bubbles of virtually empty space, bordered by titanic clusters of galaxies, the spongy material stretched around the boundaries of the bubbles. Galaxies don’t hang out by themselves but are members of small and large groups. As an example, the Milky Way, home to our sun and another 400 billion stars, is part of the Local Group, an assemblage of more than 54 galaxies which lies in the suburbs of the Virgo Supercluster. The Virgo Supercluster which has its center positioned in the direction of the spring constellation of Virgo may be also be part of an even larger congregation of superclusters known as the Laniakea Supercluster which may contain as many as 300-500 cluster and supercluster members. Beyond this we get to the universe itself which may be part of a collection of many, many universes known as the multiverse, encompassing all of the realms of space and time that lie before us. That’s the scope of our universe, but lying beneath your feet and surrounding you in every direction is another universe, the quantum universe of the very small, molecules and atoms which operate under a completely different set of rules that are absolutely essential for our macro universe to exist. For example, take hydrogen, the simplest and most common element in the cosmos. If the single proton from which it is composed were enlarged to the size of the sun, its single electron would be positioned outward almost six times more distant than Pluto. All matter, regardless of how big or small its congregation of atoms or molecules become, is mostly empty space, a tightly packed nucleus of positively charged protons and neutral neutrons, surrounded by shells of negatively charged electrons. If matter is mostly empty space, why, when you walk across your kitchen floor, or for that matter anywhere, does gravity simply not pull your body down into the Earth? At the very boundary of the floor and your feet are the shells of the electrons of the atoms which compose them. Remember in grade school when you played around with magnets and you learned that like charges repel? It’s really no different between your feet and the floor. The electrons at the outer boundary of the floor and your feet repel one another, preventing gravity from pulling you down under. This electrostatic force is stronger than the gravitational force holding you to the surface of the Earth, and so you amble about on an ultra-thin layer of electrons without ever sinking. “But wait!” you say. “How does the interior of an atom hold itself together when it is composed of positively charged protons that will also repel one another? Shouldn’t the nucleus of an atom simply fly apart?” The answer is no, not if you get protons close enough, because another force, the strong nuclear, pulls them together. Protons are kept at just the correct distance by the neutrons in the nucleus to keep the strong nuclear force working at its best. The story becomes even weirder because inside each proton and neutron there are even smaller “particles,” up and down quarks, energy strands with +2/3 charge for an up and -1/3 charge for a down—two ups and a down for a proton (+1) and two downs and one up for a neutron (0-no charge). Even electrons are not composed of matter, meaning that energy masks itself as the matter we see all around us. We live in an intricate, intertwined, grand illusion that we call reality, where nothing that we feel, see, or measure is exactly as it seems. After thinking about this for many years, I can honestly say that the one thing that keeps me from jumping off a bridge is the promise of a wise and merciful God who will one day clarify to my satisfaction all of these “entangled states.”
 

1153    SEPTEMBER 23, 2018:   Asterisms: Constellation Wannabes
I like to call asterisms, “constellation wannabes” because they are often confused by the general public as official star patterns when they are actually not. The International Astronomical Union, the worldwide congress of professional astronomers, divided the sky into 88 northern and southern constellations in 1928. They were very careful to avoid cultural influences or nationalism in their decision-making. A good example is our own Big Dipper which evolved from the pre-Civil War star group known as the Drinking Gourd, and is now visible low in the northwest right after dark. It is really the Great Bear, Ursa Major, a much more complex grouping of luminaries that are best seen in their entirety from a rural locale in the spring. The English never saw a dipper in the sky. To them, these same seven stars were known as the Plough. In early summer when the Dipper is seen cup down and handle up, the British saw the bowl as the part of the plough that cut the furrows into the verdant fields of England and the handle from which the yoke and farm animals were secured. Germans saw the Dipper as a wagon or a wheelbarrow, locating the wheel in the bucket part of the pattern. In winter the Dipper lies low and horizontal to the horizon, and it is easy to see how this design could be imagined. The Dutch saw these same seven stars as a steel pan, another straightforward conversion from our Dipper. I have even seen the Dipper denoted as the saucepan, but that may refer back to the Dutch. In Indian (India) mythology, the Dipper is known as Saptarishi or the seven great yogis, seven sages which relate to the Vedic religion, an early (1500-500 BC) form of Hinduism. One asterism that I have trouble hyping is the Little Dipper since it is composed of exactly the same stars which form the Little Bear. In Greco-Roman mythology, they represent the tail and body of the smaller bear, who was originally Arcas, the son of Zeus and Callisto. Callisto (Ursa Major) and Arcas (Ursa Minor) were changed into bears by Hera, Zeus’ wife, as punishment for Zeus’ indiscretion. Zeus then flung them up into the northern sky, their tails stretching as he swung them ever faster and faster before letting go. Another easy autumn asterism is the Great Square of Pegasus, now high in the northeast by 10 p.m. At this time of year, it appears to look more like a baseball diamond. To make it look more like a square, tilt your head to the left. Starting with the brightest star, Alpheratz, in the upper left corner, move to the upper right luminary and highest star in the rising square, Scheat. Yes, it sounds similar to that four-letter word which is not used in polite conversation, but it always gave my high school students a way out when they got a little frustrated with life. You can’t send a kid to the office if he/she is calling out the name of a star, especially in an astronomy class, can you? Moving clockwise, below Scheat is Markab. To Markab’s left, “rounding” out the Great Square, is Algenib. Alpheratz is part of the constellation of Andromeda, the Chained Maiden, but it is also used to create the body of Pegasus, the Flying Horse, to which the other three stars of the Great Square belong. Finally, there is the Pleiades star cluster which has been known since antiquity. It is mentioned in the Bible three times and known as Subaru ("to unite") to the Japanese. Better known to Americans by their more generic name, the Seven Sisters, the Pleiades become prominent in the east by 11 p.m. as a wispy, gossamer patch of sky with six faint naked eye stars, best seen with averted vision than by looking at them directly. That’s because the peripheral rods of your eyes are more sensitive to low light than the central cones which are used for visual clarity and color perception. Hosting over 1000 stars, and only 425 light years distant, the Pleiades, part of the constellation of Taurus the Bull, are only about 115 million years young. Ad Astra! Keep looking up!
 

1154    SEPTEMBER 30, 2018:   Lunar Confusion
When I first started teaching in the Allentown School District Planetarium in the fall of 1972, I found that many professionals in the elementary schools taught their students that the period of time the moon went through its phases and the time period that Luna took to orbit the Earth were 28 days. They are actually two different time intervals. The phase sequence of the moon, 29.5 days, is very different from the 27.3 days that it takes for the moon to revolve around our planet. If the two periods are added and divided by two—56.8 divided by 2—the result is 28.4 days, or 28 days if rounded to the closest whole number. The tradition of combining these two intervals into 28 days may be universally used by teachers because that is the most common first answer given by my Moravian astronomy students who come to me from many different public and private school systems. I do not want these remarks to sound condescending because the multiple hundreds of professionals that I came in contact with worked diligently to instill a love of learning among their young pupils over a wide range of disciplines whereas I have spent my entire professional career in one area, astronomy education, thinking about how to teach students to “reach for the stars” and eradicate some of these misconceptions. My conclusion for teaching young children about lunar cycles would be to ignore the 27.3-day period of the moon’s revolution around the Earth and concentrate on the 29.5-day period of lunar phases. My reasoning is simple. The 27.3-day lunar cycle is difficult to observe. In its most basic definition, it represents two transits of the moon passing a fixed point in the sky, like a star. That is a challenging observation for a novice or a child to make, especially since the moon is bright and “hides” most of the stars surrounding it. On the other hand, the 29.5-day phase period of the moon is easy to observe as we witness Luna proceeding through a day and night cycle. Yes, that is what we are actually watching, day and night on the moon as it orbits Earth and changes its shape from a new moon (no moon) through a waxing crescent (growing, horned moon), first quarter (half on, half off, light to the right), a waxing gibbous (growing and bulbous on both sides), full moon (the near side completely lit by sunlight), waning gibbous (diminishing, but bulbous on both sides), last or third quarter (half on, half off, light to the left), waning crescent (diminishing horned moon), and finally back to the new moon. The phase period of 29.5 days is directly related to our establishment of the month (from the Old English “monath,” “mona” for moon). The phases of the moon also form the basis for calculating the dates of Islamic and Jewish holidays, including the date of Easter in the Christian calendar. Also, the phases of the moon create the main “beat” for calculating when lunar and solar eclipses occur. The moon must be new, in between the Earth and the sun, and crossing the Earth’s orbital plane for Luna’s shadow to fall upon Earth’s surface to create a solar eclipse, where Sol (the sun) is being hidden—eclipsed—by the moon. Likewise, the moon must be full, opposite the sun and Earth, and crossing Earth’s orbital path for it to intersect the Earth’s shadow for a lunar eclipse to happen. Here, the moon is hiding—eclipsed—in the shadow of the Earth. All of these easily visible phenomena—phases of the moon, all lunar and solar eclipses, as well as many religious events are governed by the 29.5-day phase cycle of the moon, not the orbital period of the moon around the Earth. So, I say up with the 29.5-day lunar period for kids and save the 27.3-day orbital period for science-orientated high schoolers and college students taking astronomy courses.
 

[September Star Map]

[September Moon Phase Calendar]
 

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