StarWatch: Moravian College Astronomy

AUGUST 2020

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

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lunar phases

1250 AUGUST 2, 2020: Perseid Meteors Await: From Tuesday morning, August 11 through Thursday morning, August 13 are the big nights for the 2020 annual Perseid meteor shower. Astronomy enthusiasts call the Perseids the best shooting star event of the year, even though it does not produce the highest meteor counts. The December Geminids rank first here—burr. The temperate observing conditions of the Perseids, combined with a large number of people on summer vacation, have made it extremely popular among casual observers. It was the Perseids that got me into observational astronomy at the age of 14, when my cousin John and I discussed for months how we were going to observe them. He and his family lived north of Allentown where in the mid-60s the sky was pleasantly dark on a clear evening. Prior to the big night, that sultry summer day was capped off with a strong thunderstorm that rolled through the region during the late afternoon. It seemed for a time as if all was lost, and then it cleared suddenly, rapidly, the clouds of the storm marching away. In their wake the air became drier and the sky turned a vibrant deep turquoise blue, allowing us to view in autumn like conditions all night long. To a 14-year-old eager to look up, it was as if a miracle had just occurred. I can still remember one particularly vibrant Perseid that scorched the sky around 3 a.m., leaving in its wake a fading afterglow of its path for about 10 seconds. Man, I was hooked from that moment onward, even to the point where I deferred going to my high school prom because friends and I had planned an observing night long before the date became official. I can’t say that it was one of my wisest decisions, but at the time it made perfect sense. The best advice for Perseid viewing is not to start too early in the evening. That’s because the observer is always in the wrong position on the Earth. The analogy is similar to being in a vehicle moving through a downpour. It is the front window that seems to be getting all of the raindrops as you plow through the deluge. The back window only gets a drop here and there because it is shielded by the front of the car. Likewise, in the early evening we are being protected by the Earth because our position is analogous to watching meteors from a car’s rear window, reducing meteor activity. As local midnight approaches, the Earth slowly makes its rotational debut into the meteoroids, bringing us to the front window location with a resultant increase in activity. This year, it is the morning of Wednesday, August 12 about 2 a.m. which is the focus of peak activity. That is very good for East Coast observers since by then the Earth will have turned into its front window position. The only negative astronomical detractor during the evening will be the moon, just a day past last quarter. A quarter moon is just under 10 percent the radiance of a full moon. On the morning of the 12th, Luna will be in Taurus the Bull, not that far from Perseus, the region of the sky from which the meteors will seem to be diverging. The idea will be to keep the moon away from your field of view so that your vision remains unaffected by its light. The highest Perseid rates that I have ever experienced were about one meteor per minute; however, these shooting stars have the tendency to bunch with several events happening within a short interval of time, followed by a period of as long as 10 minutes where no activity occurs. Back in 2016 when I observed the Perseids from Flathead Lake in northwestern Montana, I saw six shower meteors within a 15-second interval. I was actually crashing a wedding with my traveling companion, Pete, who was best man. Pete had fallen asleep. In the commotion that ensued—and it was very exciting, and I’ll admit somewhat loud, I woke up the bride, whose room was about 100 feet from where we were observing. She emerged ghostlike with some of her entourage and quickly began admonishing Pete for talking too loudly. It was really a priceless moment. Read about the story here, https://www.astronomy.org/StarWatch/September/index-9-16.html#9-11-16. More about the Perseids and how to observe them next week.

1251

AUGUST 9, 2020: Cosmic Drive-In: The Perseids

This is the week (August 11-13) that Perseid meteors will be visible in their greatest abundance. If your locale is rural enough, they will be seen against the backdrop of the summer Milky Way and with a third quarter moon visible in the morning sky. Regardless of the moon, they are still worth an hour or two of viewing, especially on the morning of August 12 after 1 a.m. when the shower activity will be peaking. Dust off the chaise lounge or that folding recliner, find a sleeping bag or bedroll, use a pillow for comfort, a light tarp in case of dew, and perhaps have a caffeinated beverage handy and you’re all set. Right after dark is not the best time to observe meteors, but it may be the only opportunity available depending upon your schedule. Perseids will still be seen, but rates are suppressed at this time of the evening because our location on Earth physically blocks much of the activity. Also, the region of the sky from which the meteors seem to originate called the radiant is just rising, so we do not catch any of the activity which is happening below this region because of the obstructions that trees, buildings, and the horizon provide. This also reduces meteor rates. Face your recliner towards the NE, and observe the area of the sky which is overhead because from a suburban locale this is the darkest region of the heavens. Keep the moon from your line of sight. Before midnight, Perseids will seem to spray upward and outward from a vanishing point in the NE, close to the horizon and from all directions, high in the east by dawn. The effect is analogous to standing on a long stretch of railroad tracks. The rails approach and pass you on either side, appearing to diverge from a distant vanishing point, even though you know that they must be parallel in order for a train to travel over them successfully. Likewise, Perseid meteoroids, the tiny bits and pieces of silicate dross released by Comet 109P/Swift-Tuttle, are moving parallel to each other as they orbit the sun. Just like railroad tracks, these meteors will appear to diverge from a vanishing point called the radiant as they approach you. This area of the sky is below the constellation of Cassiopeia the Queen and just above the head of Perseus the Hero. Any shooting star that can be traced back to this region is most likely a Perseid. Both of these constellations will be difficult to spot at 10 p.m., but by 1 a.m. they will have gained altitude and should be visible even from suburban locales. Cassiopeia will be easier to visualize, partly because of its higher elevation and partly because it has a distinct sideways “W” or an “M” appearance. Perseus will have a triangular-shaped top (his head) which will spread outward in two lines curling at the end for his winged feet. A map is online at https://astronomy.org/StarWatch/August/index-8-20.html#8-9-20 to help you to visualize their shapes and better access a more precise location of the radiant. By 3 a.m. the top of Perseus will be above mid-sky, and you will be catching shooting stars all around the radiant. Meteor rates will also be much higher because our region of Earth is plowing into the meteor stream. Perseids are fast movers, entering the Earth’s atmosphere at 36 miles per second, causing a column of air about a half mile wide, 70 or so miles above the Earth’s surface, to glow as their fragments ablate, vaporized by the friction created by the air during their descent. A Perseid meteor may be visible for only a tenth of a second, a momentary blip on the radar of your visual acuity. Others will last longer, causing the atmosphere to ionize so completely that the glow of its track will be visible for several seconds after its flight to oblivion. Sometimes, you’ll see bright meteors blink from the corner of your eye, and at other times, you’ll see an extremely faint event because you are looking directly at it. You might even see a point meteor, a shooting star coming straight at you from the radiant, a “star” that will appear to brighten slowly, then fade precisely at the location where all of the other meteors appear to be diverging. Most of all, a night with the Perseids will produce a memorable experience, with several of the fireballs seen that evening etched into your recollection for the rest of your life, the event instantly available to regale others with the wonderful encounter you had on the night when the Perseids “flew.”

The map shows the location where Perseids will be flying. Gary A. Becker map using Software Bisque's, The Sky.

1252 AUGUST 16, 2020: Science: Observe, Deduct, Adjust: I recently started reading an article about why students don’t like science. Foremost in my mind, there was the obvious math stigma, but that is not how the article began. It stated that in order to get students to think like scientists, they had to first achieve peer permission. In other words, their friends and close associates had to think that what they were doing was cool so that they would feel comfortable in relating to science. This to me complicated the matter because it encouraged a herdlike mentality that “punished” the individual thinker. If I had to boil down the scientific process to just one word, it would be simply OBSERVE, or three words, OBSERVE, DEDUCT, ADJUST. Any reasonably intelligent person who begins to observe the world around him or her is bound to see relationships. And here is the main point; putting those relationships into a practical perspective, to allow oneself to make deductions to live a better life, is in essence what science is all about. Science really can be fun and save your life at the same time. No, discovering a vaccine for COVID is not that simple, but bowing your head to a smartphone while walking down a darkened street at night is an invitation to being mugged and maybe tripping over an uneven sidewalk. I am no Albert Einstein, but I do consider myself a fairly good observer. When I present, trying to make astronomy fun and enjoyable for my students, I am receiving a myriad of signals from my audience, from the pupil who has his head buried in his computer, who I know is somewhere else, but I can’t prove it, to the learner who is sitting at the edge of her seat grabbing at every concept that I’m trying to convey, and then asking questions when my point is not driven home to her satisfaction. When I taught in the Allentown School District Planetarium at Dieruff High School, I became known as AccuBecker for my winter weather forecasts. Kids who I had never seen before would come up to me and ask if we were going to have a delay or have off from school the next day. Yes, I could read a weather map, make deductions from the loops that I had watched, understand how the sky changed as the inclement weather approached; but there was one more aspect of the forecast that no one took into consideration, and that was the psychology of the decision-making process. No administrator wanted to share the burden of having elementary students get hurt on their way to school during a winter weather event. Once that was factored into my mental rubric, I was virtually always correct in my decisions. Whether a physics or chemistry teacher would call that science may be up for debate, but I followed the rules. I observed, made deductions, created a hypothesis, tested it when winter weather approached, and made modifications to improve my predictions. I think in a way many of us “do” science subconsciously to make our lives better, more productive. and more satisfying. It is that we just don’t realize the process and how it could be expanded to help us even more. Now in the COVID era with Zoom, I’ve got to add power disruptions into my formula too! Bummer...! Happy fall term to all and keep observing, deducting, and adjusting, and you’ll be a practical science enthusiast without even knowing it.

1253 AUGUST 23, 2020: Robert Brown: A Personal Reflection: I had just signed a contract to teach at Broughal Junior H.S. in Bethlehem, PA. It was the early summer of 1972, and I was fresh from my college graduation. When I got home, there was a written message waiting for me. The assistant director of the Allentown (PA) School District Planetarium had just been promoted to assistant principal of Dieruff H.S., and there was a vacancy at the planetarium. I interviewed the following morning, and by evening I had teaching positions in both cities. Bethlehem released me without prejudice, and it was as assistant director of the planetarium that I began a wonderful six-year association with Robert (Mike) Brown, the ASD Planetarium’s first director. Mike had been a biology teacher at Dieruff who was championed for the “machine seat” when the ASD Planetarium first opened in September of 1965. He was meticulous about its operation and maintenance. With Sputnik and other Soviet space firsts nagging at America’s conscience, Robert Brown was nearly worked to death in those first years. Everyone wanted a program inside Allentown’s new star vault, and so an assistant was hired. When I came on board in 1972, the program was a well-oiled operation with a master craftsman at the helm who was willing to share his knowledge and also readily incorporate my ideas into the program. That taught me a lot about leadership and teaching. Find what your subordinates do best and nurture it. Coach in areas of weakness, but never with a superior attitude. Mike untethered the ropes and let me fly. In his soft-spoken style, he would tell me to chart my own course, but listen to the suggestions of the other people around me. Don’t be vindictive. Reach for the light. Observe and learn from your students as you try to educate them. Be kind to others. Say, “Thank you.” However, there was another connection which I had not fully considered until I read of his passing last week. I met my wife, Susan, through astronomy. After graduating with a business major from Central Catholic in 1967, she was hired to work in the Xerox department of Lehigh Structural Steel as a temporary replacement for an employee on vacation. Although the job was enjoyable, it was not long before she realized that her career path lay in a different direction. After seeing Saturn through a neighbor’s telescope as a child, Sue decided to enroll in a descriptive astronomy course sponsored by the Allentown School District Planetarium, and Mike Brown was the gracious instructor who further nourished her interest in the subject. She went on to college and graduated with a secondary education degree, certified to teach English, but her passion regarding astronomy, fueled by Mike, never faded. A decade later, I would meet her at an astronomy presentation that I was giving for the Lehigh Valley Amateur Astronomical Society as she was continuing her quest to learn more about the heavens. Meeting Susan was the best thing that ever happened to me in my life. Working with Mike Brown was a life-changing experience. God bless you, my friend. Ad Astra!

1254 AUGUST 30, 2020: Put Mars on Your Radar: If you are outside by 9 p.m., you will notice Jupiter on prominent display low in the south. To its left, and slightly beneath, separated by a fist held at arm’s length will be Saturn, considerably fainter, but nonetheless, still prominent. The two planets will continue to approach one another coming to within 1/10-degree separation, low in the southwest on the 21st of December, the shortest day of the year. Let the Earth rotate for another two hours (11 p.m.) and look to the east, where a bright reddish star will be appearing about 15 degrees above the horizon. That’s Mars which has been growing more vivid in the morning sky, as the faster orbiting Earth approaches, and eventually passes the Red Planet on October 13 at only 38.6 million miles distant, and shining nearly twice as bright as its current reflective luminescence. It was still much better on August 27, 2003 when the Earth approached Mars to a record 34.65 million miles. It was the closest “flyby” of Mars by Earth in recorded history, in fact, the closest approach in 60,000 years. In just over a week on September 9, Mars begins to retrograde or move backwards in the sky. The planet’s motion against the backdrop of stars is normally toward the east, but as Earth has been approaching Mars, its direct movement has slowed and will stop on the 9th as the planet begins to move towards the west. The analogy is similar to passing a slower moving car on the highway. Pulling into the left lane to execute the maneuver, the car being passed appears to shift backwards with respect to the faster speed of the passing vehicle, even though both cars are moving in the same direction. Mars’ retrograde movement continues until mid-November when it will once again assume its direct or eastward path. All of the superior planets in the solar system, those worlds farther from the sun than Earth’s orbit, perform this backwards dance, but because of the closeness of Mars to the Earth, its retrograde loop is by far the most impressive and easiest to witness. Mars is nearest to Earth on October 6, then eight days later on the 14th, Mars is at opposition, 180 degrees from the sun, opposite to Sol, rising as the sun sets and setting the following morning when the sun rises. This happens every month for the moon when it is in its full phase. Speaking about Luna, it will be in conjunction (together) with Mars on Sunday, September 5. From 11 p.m. on September 5 through 2 a.m. on the 6th, Luna and Mars are within one degree of each other. In those three hours it will be possible to witness the orbital motion of the moon carry Luna past the Red Planet, moving from Mars’ right to its left. It will be a beautiful sight through binoculars, spotting scopes, and wide field telescopes. You won’t be disappointed. Ad Astra!