Skywatch week of September 9th, 2019
Mon Sep 9, 2019 STAR TREK
The first Star Trek TV episode aired on September 8, 1966. I saw that first episode, which was about an alien that would suck the salt out of you when you weren’t looking. So of course, like many young space enthusiasts, I was immediately captivated. I liked the show’s vision of a promising future (not counting the part where you get the salt sucked out of you,) and the portrayal of humans as daring explorers of the galaxy, curious about what they would find out there. The science and astronomy in it showcased the beauty and vastness of outer space – grand nebulas, lush planets, exotic moons. The writers built on the best of classic science fiction, and the science was, for the most part, well-researched. There were no intergalactic aliens in Star Trek (well, once or twice, like with the Kelvins, but they were from the nearby Andromeda galaxy, so that was kind of like getting to know the neighbors next door.) The writers understood that our Milky Way alone, was big enough to contain us. For now, anyway.
Tue Sep 10, 2019 THE ASTRONOMER’S ALPHABET – L
Today’s astronomy alphabet is the letter “L.” “L” is for “Light Year,” the distance that a photon of light can travel in one earth year. At 186,000 miles a second, light traverses nearly 6 trillion miles – that’s 1 light year. “L” is also “Luminosity,” the amount of energy emitted by a star – and not just the light we can see, but also radio, infrared, ultraviolet, x-ray and gamma! “L” stands for “Lunar,” anything to do with “Luna,” the moon. For instance, the moon exhibits “libration,” a sideways oscillation that the moon displays as it orbits. The moon always keeps the same half facing us, but, like a roulette ball settling into a pocket, it slowly shimmies a little, which allows us to peak around the moon’s “Limb,” the edge of the moon, letting us see nearly 60% of its surface. “Local Group” begins with “L.” That’s a few dozen nearby galaxies, including the Milky Way, the irregularly-shaped Clouds of Magellan, and the great spiral Andromeda galaxy, that are gravitationally bound together. Lovely!
Wed Sep 11, 2019 SCUTUM
The fifth-smallest constellation in the sky is very difficult to see, but it has an interesting history. Scutum, the “shield of Sobieski,” has no bright, or even middling-bright stars within its borders, and as it’s wedged into the summertime Milky Way, between Aquila the Eagle, Sagittarius the Archer and the Serpent’s Tail, (Serpens Cauda,) finding it is more like a process of elimination than actual discovery. It was introduced to star charts by the astronomer Johannes Hevelius to commemorate the lifting of the siege of Vienna which had happened on September 12, 1683. King Jan Sobieski of Poland led his hussars and men gathered from England, France, Germany, Austria, and even a great many displaced Tatars who had settled in Poland, in an attack that routed the Turkish army, which had lain siege to Vienna. Scutum has a couple of open star clusters – M11 (the Wild Duck Cluster,) and M26; the globular star cluster NGC 6712, plus a planetary nebula, and even a pulsar.
Thu Sep 12, 2019 ELEVEN DAYS MISSING!
Did you know that here in America, there was no September 13th in the year 1752? There wasn’t a 12th either, or a 10th or 11th, nor a 3rd through the 9th! It happened when the Gregorian calendar replaced the Julian calendar. The Julian calendar, established by Julius Caesar seventeen hundred years earlier, was inaccurate; it was behind by ten days when Pope Gregory introduced the Gregorian calendar to Catholic countries in 1582. But England and its Protestant colonies ignored the papal edict, and kept using the old Julian calendar, until 1752, when, in order to fix the calendar, eleven days had to be chopped out. Riots broke out in London as landlords charged their renters a full month’s rent, even though the month was just 19 days long. “Give us back our eleven days!” they shouted. But in America, Ben Franklin counseled his readers not to “regret.. the loss of so much time,” but to give thanks that one might “lie down in Peace on the second of the month and not… awake till the morning of the 14th.”
Fri Sep 13, 2019 SEPTEMBER FULL MOON
The moon is full tonight. September’s full moon is the Barley Moon of medieval England, or the Singing Moon in Scotland and Ireland. The Chinese call this the Chrysanthemum Moon, while in the Americas it is the Black Butterfly Moon or the Nut Moon of the Cherokee. Similarly it is the Little Chestnut Moon of the Creek and the Seminole people. It is the Drying Grass Moon of the Arapaho and the Cheyenne people, and the Choctaw Indian’s Courting Moon. While the Comanche say it is the Paper Man Moon, the Mohawk call September’s Full Moon the Time of Poverty. To the Omaha Indians it is the Moon When the Deer Paw the Earth while the Sioux say it is the Moon When Calves Grow Hair. This is also the Harvest Moon, the full moon which occurs nearest the autumnal equinox, the beginning of fall, which will be on September 23rd. The light of this full moon proved helpful to farmers who brought in their harvest of crops after sunset.