[image: apollo-and-king-midas-by-simon-floquet-c-1634_1_orig.jpg] *King Midas: Be careful what you wish for...* If one had asked King Midas to describe himself in two words, he would have replied, "Nice, but not too bright." Of course, his intellectual limitations led him to such an ignominious fate that he remains one of the few mythological figures well known today. In fact, the phrase "Midas touch" is a complimentary one as it denotes the rare person who finds success at any venture with little or no effort. Midas, himself, wasn't one of these people. He was the king of Phrygia, a beautiful realm known as the "land of roses." Midas was a kindly king fond of lush gardens and lacking in any martial ambitions. Consequently, his was a peaceful kingdom abounding in natural riches. One day Silenus, an old, hefty and perpetually intoxicated follower of the wine god Dionysus, stumbled into the palace's rose garden and fell fast asleep. He had been a part of Dionysus' frenzied and besotted entourage until he lost his way as his fellow wine worshippers danced through Phrygia. When poor Silenus awakened, he found himself wreathed in roses and a wrapped in a tunic much too small for his body. Servants had happened upon him as he slept and decorated him absurdly in his slumber. When Midas saw the old man so preposterously attired hobbling toward the palace , the King approached him gently. Midas didn't ridicule Silenus, but instead welcomed him warmly into his home. Silenus remained in Midas' palace for ten days, during which time he was given ample food, clothing and, of course, a surfeit of wine. On the eleventh day of Silenus' stay, Dionysus arrived at the Midas' palace The god had heard of Silenus' whereabouts through the grapevine (hence the saying) and had come to collect him. Dionysus was so gratified to have seen his follower kept safe and nourished that he offered King Midas one wish. Midas quickly said, "I want everything I touch to turn into gold." Dionysus granted the wish at once and then took his leave with Silenus in tow. Delighted at his new power, Midas ran through the palace touching plates and glasses and tables, all of which were transformed into gold. "I shall be the richest man in the world!" Midas exclaimed joyfully as he sat down to dine. He picked up an apple, only to have it turn into gold, rendering it inedible. Suddenly, Midas realized his folly. He looked onto the luscious food and knew he couldn't eat any of it, for any morsel would become gold at the slightest touch. Fearing imminent starvation, Midas prayed aloud to Dionysus to take this new power away. Dionysus, who was expecting to receive this desperate prayer, instructed Midas to wash his hands in the Pactolus River. Midas rushed to the river and by submerging his hands in its waters lost his golden touch. Ever since, prospectors always found plentiful gold supplies in the Pactolus' riverbed. Later, Midas would go on to have another misadventure. He was selected to serve as one of the judges in a musical contest between Apollo and Pan, god of the wilderness and rustic music. Although Pan's flute playing was melodious and soothing, Apollo's harmonies were more beautiful than any other music save, perhaps, that of the muses. , The mountain Tmolus, chosen to be the main judge due to its advanced age and wisdom, awarded the prize to Apollo. So, too, did everyone else in attendance, except for Midas. "I thought Pan's performance to be finer," he insisted to the shock of the crowd and to Apollo's chagrin. "Only a donkey would prefer Pan's music to my own!" Apollo raged. To his shame, Midas found that he sprouted donkey ears in place of his own. "Apollo, your music was by far the superior," Midas then cried. "Please remove these horrid ears!" Apollo, far less gracious than Dionysus, laughed and vanished. For the rest of his life, Midas sported donkey ears, which he hid under cap. Nobody in his kingdom was permitted to mention them. However, one day the servant tasked with cutting Midas' hair, saw the ears. After he cut the king's hair, the amused servant rushed outside, dug a hole in a marsh and spoke of the king's misfortune into it. It is said that even today whenever wind strikes the spring reeds growing from the marsh, one can faintly hear them murmuring, "King Midas has donkey ears...." THE SOUTHWORTH PLANETARIUM 207-780-4249 www.usm.maine.edu/planet <http://www.google.com/url?q=http%3A%2F%2Fwww.usm.maine.edu%2Fplanet&sa=D&sntz=1&usg=AFQjCNHulkHuLP13bOG2PkNrPazsGWFs2A> 70 Falmouth Street Portland, Maine 04103 43.6667° N 70.2667° W Altitude: 10 feet below sea level Founded January 1970 Julian Date: 245961.16 2019-2020: CXXXI THE DAILY ASTRONOMER Wednesday, April 22, 2020 Remote Planetarium 18: The Science of Solar Eclipses [image: 3762c.jpg] Solar eclipses are simple in concept, yet complicated in application. They occur when the moon moves directly in front of the Sun from Earth's perspective. A solar eclipse can only occur when the moon is at conjunction (new moon) and it at or near a node, the intersection point connecting Earth's orbit and the moon's. Solar eclipse don't occur every month because the moon's orbit is inclined to Earth's orbital plane by slightly more than five degrees. Generally when the moon is new, it will be north or south of this plane and no eclipse will occur. [image: download.jpg] If the moon's orbit were precisely aligned with Earth's orbit, eclipses would monthly occurrences. We recognize four basic solar eclipse types: - *TOTAL:* when the moon completely covers the Sun - *ANNULAR:* when the moon moves directly across the Sun, but appears smaller than the Sun. At totality, the moon is surrounded by a ring of sunlight. - *PARTIAL:* when the moon only partially covers the Sun - *HYBRID:* when the eclipse is annular and total during the same eclipse. Even though we could devote an entire course to solar eclipses, today we are going to focus on total solar eclipses. The map below pertains to the April 8, 2024 eclipse: a rather important one as it will -weather permitting- be visible in Maine. [image: SE2024Apr08T.png] Any observer within the region under the blue grid will be able to observe the eclipse. What the observer actually sees will depend on his/her location. Anyone within the dark blue arc extending from the Pacific to the north Atlantic will see a total solar eclipse. That blue arc defines the* totality path*, the only place where the eclipse appears total. We can see that western and northern Maine are within the totality path. The Portland area will not be. Observers outside this arc will see a partial solar eclipse, the magnitude of which depends on the observer's distance from the path. For instance, an observer standing somewhere along the 0.8 line (running through Mexico, Alabama, Georgia, South Carolina and North Carolina) would see an eclipse of magnitude 0.8, meaning that the moon will cover 80% of the Sun's diameter. As another example, an observer along the 0.2 line (perhaps British Columbia or Costa Rica) would see the moon cover only 20% of the Sun's diameter. Any observer north of the top blue line or south of the bottom blue line won't see any part of the eclipse at all. - The totality path is within the* umbra*, the darkest part of the moon's shadow - The other regions in which only partial eclipse will be visible is within the *penumbra,* the outer part of the moon's shadow. [*Important note:* Magnitude is NOT the same as Obscuration. Magnitude measures how much of the Sun's diameter the moon covers. Obscuration measures the amount of the solar disk the moon covers. Example, if the eclipse magnitude is 0.5, the obscuration is about 39.1%. [image: EclipseMagnitude.jpg] We can see that when the moon covers half the Sun's diameter more than half of the Sun remains visible.] *THE APPEARANCE:* [image: total-solar-eclipse.jpg] During a total solar eclipse, the moon completely covers the Sun. During totality the corona, the outermost part of the Sun's atmosphere, becomes visible. The sky darkens enough to render the stars visible. [image: solar_shades_plastic.jpg]*Safety note: * While eclipse glasses are certainly necessary to safely watch the eclipse prior to and after totality, one may safely observe the Sun during totality PROVIDED that one looks away before totality ends. Be sure not to look at the Sun without protection when totality ends. Even the sunlight emitted by the thin crescent that emerges just after totality can damage your eyes. *THE FREQUENCY* At least four eclipses will occur each year. On rare occasions as many as seven eclipses occur in a year. During minimum years (only four eclipses), two will always be solar eclipses and the other two lunar eclipses (the passage of the moon through Earth's shadow.) A solar eclipse and a lunar eclipse will be separated by two weeks because each eclipse type happens when the moon is at or near a node. Earth's orbit and that of the moon are connected by two nodes separated by 180 degrees, the same separation distance between new moon and full moon (the moon phase during a lunar eclipse.) *THE SAROS CYCLE* We can predict eclipses because of the Saros Cycle. An eclipse with the same geometry will repeat every 18 years, 11 days and 8 hours. We know that a solar eclipse can only occur when the moon is new and at or near a node. However, an eclipse can occur at any point in the moon's orbit. Sometimes eclipses will occur when the moon is at or near *perigee (*the point of least distance) or at *apogee* (the point of greatest distance) or somewhere in between. Eclipses within the same saros cycle will occur 18 years, 11 days and 8 hours apart and at approximately the same distances. This time period corresponds to: - 223 synodic months (a *synodic *month equal to the time period separating successive new moons. Approximately 29.5 days) - 242 draconic months (a *draconic* month is equal to the time period the moon requires to return to the same node. Approximately 27.2 days) - 239 anomalistic months (an *anomalistic* month is the time period separating successive perigees. Approximately 27.5 days.) The April 8, 2024 solar eclipse is part of Saros cycle 139. The first eclipse in this cycle was a partial solar eclipse that occurred on May 17, 1501. The last eclipse will be another partial scheduled for July 3, 2763. The eclipse prior to the April 8, 2024 event occurred on March 29, 2006. The one after will happen on April 20, 2042. Based on this Saros cycle, can you predict when the next one will occur? *Answer: * April 30, 2060 *EXELIGMOS* Note that the period of a Saros cycle is 18 years, 11 days and 8 hours. As eight hours equals one third of a day, an eclipse in a given Saros Cycle will be displaced by about 120 degrees relative to the previous eclipse. However, every third eclipse within the same Saros will be visible within the same general area. Or, every eclipse separated by 54 years and 33 days will have similar geometries and will be seen in the same part of the world. However, their respective totality paths will be displaced. We call this 54 year 33 day time period as one "exeligmos," from the Greek for "turning of the wheel" [image: download.png] The above image shows the totality paths for nine successive eclipses within Saros Cycle 136. We see that each eclipse within this saros is displaced by about 120 degrees relative to the one prior and the one following. However, every third eclipse happens along the same part of the planet. Notice that the June 8 1937 eclipse is south of the July 11 1991 eclipse which is south of the August 12 2045 eclipse. Each of these eclipses are separated by one Exeligmos. Tomorrow we'll discuss in more detail lunar eclipses, the eclipses that occur when the full moon moves into Earth's shadow. 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