StarWatch: Moravian College Astronomy

StarWatch for the greater Lehigh Valley

AUGUST 2014

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

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937 AUGUST 3, 2014: Big, Bright Full Moon, August 10: My wife, Susan, recently commented that I am far too optimistic about my desire to get people to observe the sky during the summer months. She added that a more appropriate statement might be to “look up and view the haze.” Alright, so summer does have its pitfalls with regards to seeing stars. Mist, humidity, fog, thunderstorms, and just plain cloudy nights all contribute to the difficulties of seeing the heavens during the warmer months. Add to that as a personal aside, 10 days of pristine late June observing under the dark skies of the Utah desert, and even I sometimes question my motives for looking up when I’m back East. This week, however, it’s different. Unless clouds vault the heavens, it should be easy to watch the moon wax to its full phase on August 10. What is interesting about this full moon is that it occurs at a time when Luna is at perigee, closest to the Earth, and therefore, bigger and brighter in the sky. The moon circles Earth in a period of 27.3 days, but because Earth changes its orbital position with respect to the sun during this time, it takes the moon an extra 2.2 days to realign itself into the same phase configuration. This causes the period of time from full moon to full moon to be longer, 29.5 days to be more precise. While the moon revolves around the Earth in its elliptical (oval-shaped) orbit, its distance is changing in a time period which is different from its orbital and phase intervals. The time from perigee to perigee takes 27.6 days. If you think of these rhythms as drumbeats, it means that every couple of years the drumsticks hit the head of the drum precisely in sync, i.e., the moon is full and closest to the Earth at the same time. This creates what is called a perigee full moon, and it is bigger and about 30 percent brighter than an average full moon. So if the full moon appears extra big and extra bright when it rises on August 10, remember that this time it will be due partly to an illusion, and partly to reality.

938 AUGUST 10, 2014: Dog Days Not All about Heat: Here’s a sobering bit of news. The “dog days of summer” are nearly over, and if you’re a teacher like me, the beginning of the fall semester lies barely two weeks into the future. The dog days to us represent the hottest part of the year which is defined as the period from July 3 through August 11. In the continental US only southern New Mexico, Arizona, and West Texas max out before the dog days while parts of the Texas and Louisiana Gulf Coast peak after these times. The dog days really have a more ancient origin dating back to the unification of Upper and Lower Egypt over 5000 years ago, and they were not so much heat-associated, but rather linked with the rising of Isis (now Sirius the Dog Star) and the flooding of Egypt’s lifeblood, the Nile River. Isis, who was Osiris’ wife, was instrumental in the resurrection of her husband, god of the underworld, after he was murdered and mutilated by his brother Set. It was believed that the Nile River flooded each year because of the tears cried by Isis for Osiris when her star rose heliacally, at the same time, as the sun. Ancient Egyptian astronomers would wait patiently for Sirius, the brightest star of the night, to be seen just before it was washed from view by the luminescence of the impending sunrise. This event reset the Egyptian solar calendar, but it also serendipitously coincided with the flooding of the Nile which provided the rich nutrients that would sustain another growing season. The heliacal rising of Sirius (Greek for searing) would have occurred shortly after the summer solstice in 3000 BC, and moved deeper into July as the millennia passed. This was Egypt’s warmest time. For Egypt today, the first glimmer of Sirius before sunrise occurs in late July to early August. For most mid-latitude US observers, that time should be happening this week. Now you have a more complete story behind the dog days of summer. Woof, Woof!

939 AUGUST 17, 2014: Life of Flight Sputters: I just finished Jay Barbree’s, Neil Armstrong: A Life of Flight, Thomas Dunne Books, (2014) after completing James R. Hansen’s work, First Man: The Life of Neil A. Armstrong, Simon and Shuster (2005) about a year ago. On the front cover both books show an image of Armstrong’s contemplative face taken through his transparent spacesuit helmet as a Gemini pilot, but Hansen’s is in color while Barbree’s is in black and white. That may best sum up the portrait each author weaves of Armstrong in its completeness and detail. Barbree’s work definitely deserves to be in b/w. In defense of Barbree, his strongest asset is his ability to integrate the achievements of Armstrong against the backdrop of the US and Soviet space programs, and rightfully so. Barbree, as an NBC News correspondent, covered all 166 “manned” spaceflights right through the end of the Shuttle program. But when Barbree has Armstrong contemplating black holes and dark matter as he looked from the window of his Apollo spacecraft, it made me shudder. Both concepts have much earlier origins, but their realities don’t take shape until the ‘70’s for black holes and the ‘90’s for dark matter. Barbree also makes Armstrong look more like he was just one of the guys, when in reality, Hansen meticulously details Armstrong as social but not gregarious, measured in speech, a perfectionist who focused on getting it right, and above all a reluctant hero who felt that his accomplishments were gleaned as much from a factor of chance as they were from experience. Both authors rightfully conclude that Neil Armstrong was the best fit for representing humankind as the first moonwalker. Those traits were also my impressions when I heard him speak and briefly had the opportunity to talk with him in June of 1973. Armstrong died of complications resulting from vascular bypass surgery on August 25, 2012. He was cremated and buried at sea.

940 AUGUST 24, 2014: Swing High, Swing Low: If you haven’t noticed the rapidly shrinking daylight, then I suggest you pop your head out-of-doors just after 8:30 p.m. It’s dark! The latest sunset occurred on June 30 at 8:33 p.m. for 40 degrees north latitude. Sunset at the beginning of this week happens at 7:47 p.m., but by week’s end ole Sol’s hitting the dirt 10 minutes earlier. The changes in the dwindling daylight will occur faster and faster until the autumnal equinox (September 22), and then begin to slacken until the winter solstice (sun standstill) which occurs on December 21. It’s similar to a child on a swing gliding back and forth. At the top of the arc, the swing momentarily stops at its farthest distance or amplitude from the center. These are the solstices, summer and winter, when the sun stops its northward or southward motions. Not much changes on either side of the solstices, again similar to a swing at the top of its arc. The swing’s velocity slows, comes to a stop, and then gradually increases once again on its downward path. The maximum velocity (change) happens at the bottom of the arc, which corresponds to the autumnal (fall) and vernal (spring) equinoxes. So although the sun is now on its downward slide, the biggest decrease in daylight will not occur for another four weeks. By mid-October the changes will be as rapid as they are right now. While you take note of the shrinking daylight, take a look at the sky around 8:30 p.m. You’ll notice two bright starlike objects close together in the southwest. The luminary below and to the left is Mars, while its companion is Saturn. The planets will be near to each other throughout the week, but on Monday the 25th, they will be closest, just 3-1/2 degrees apart. That’s about the separation of your thumb held at arm’s length. The view becomes even more interesting when the crescent moon enters the scene on the 30th, and then stands above and between the pair on Sunday, August 31. Good observing!

941 AUGUST 31, 2014: In the Year 2228...: “Wasn’t Captain Kirk of Star Trek fame born in Iowa,” I mused? My mind flashed to the movie scene where an adolescent Kirk pursued by a cop drove his dad’s antique car off a cliff. But that was in dry canyon country, and Iowa was so green with corn, and more corn, and even more corn. “Hollywood,” I chuckled. “Yup,” my friend, Pete Detterline said. A quick Google search showed Riverside, Iowa, pop. 1040, as the spot, and it would happen on March 22, 2228. “A plaque behind a former barbershop marks the place,” Peter read. Riverside was also close to the Mississippi, and we were westbound, already nearing the drier Nebraska border. Pete noted that another marker under a pool table at Murphy’s Bar and Grill indicated the location where the future conception would take place. Riverside even wanted to build a bronze Kirk bust commemorating his future achievements, but Paramount Pictures kiboshed the idea by wanting to slap a $40,000 licensing fee on the project. The proposal fizzled like Alka-Seltzer in ole Mississippi mud water, but Riverside was officially sanctioned as Kirk’s future place of birth by Star Trek creator, Gene Roddenberry. The fact that all of this upcoming history was positioned so close to our return path from the dry deserts of Utah was just too much to resist. So we diverted and stopped in Riverside on our return trip. We had a late lunch of meatloaf and iced tea at Murphy’s Bar and Grill. And yes, the placid barmaid pulled out the well-worn conception plaque and told us “where to go” to see the official birthing location, behind a beauty shop, not a barbershop. And yes, it was there to photograph in all of its splendor, so that we could regale this important information to our future students. Numerous hours later as we were leaving Riverside, a big, red and rusty dump truck threw a stone and cracked the front windshield of my Jeep. Thanks for those future memories, J. T. Kirk! Photos are online.

[August Star Map]

[august Moon Phase Calendar]