StarWatch: Moravian Univerity Astronomy

JULY 2021

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1298 July 4, 2021: Icebound: The Dutch explorer and navigator, William Barents, was the central figure of three polar expeditions in the late 16th century to secure a passage to the Far East, not around Africa, but northward over the Pole or eastward through the Kara Sea north of Siberia. His expeditions are vividly captured by Andrea Pitzer in Icebound: Shipwrecked at the Edge of the World, Scribner, 2021. If this were a fictional novel, it would be over the top, too unbelievable with details of deprivation from the cold, continuous delays caused by shifting ice, and stealthy attacks by ravenous polar bears. • The book also provides a window into the transitional thinking of science a century after Columbus rediscovered the Americas. On all three voyages, members of Barents’ contingencies kept meticulous records, allowing Pitzer to recreate the expeditions in minute detail. Barents is described as a person who could make observations of the sun and place a ship’s position on a globe. “He could watch the stars and tell [his crew] the day of the year. He knew when the sun was in its fixed place and when time had slipped out of kilter.” In contrast to these keen observational attributes, Barents also believed that if he sailed far enough north, the ice would vanish, and he and his companions would have a safe passage over the “temperate” North Pole to the Far East. • Navigation in the late 16th century was not only a science but also an art. Angle measuring devices, such as cross staffs and astrolabes, were used to find the altitude of the sun and brighter stars, especially the North Star. Used in conjunction with the ship’s clock and correction tables, latitude, which is the location north or south of the equator, could be established reliably. However, to obtain an accurate longitude position, east or west of a known position, a clock had to be carried onboard the ship which kept the precise time at that location. This could not be accomplished in Barents’ time and would not be feasible until the completion of the first marine chronometer by the British clockmaker, John Harrison, in 1735. • If William Barents knew the latitude of a destination, he could find a similar latitude by measuring the sun’s altitude. Afterwards, he could dead reckon, using a compass for direction until land came into view. Then the ship would hug the coastline with the navigator sighting known locations on charts brought along for the voyage. If no chart existed, it was paramount that one be created for future reference, such as Barents did for the Nova Zembla archipelago (Novaya Zemlya in Russian), where he was shipwrecked at its northeastern end with 16 others crewmates during the winter of 1596-7. • Barents’ idea of a northern route to the Far East was 400 years premature. The eternal ice that plagued his three voyages and prevented him from reaching his goal is no longer present off the coast of northern Siberia during the summer. In fact, sailing across the North Pole in ice-free waters may occur in just one to three decades due to climate change. If you are into adventure, surviving brutal cold and savage polar bears, being shipwrecked in eternal darkness, and overcoming death scores of times, then Icebound is a must read. Once started, it was a book that was impossible to put down.

1299

July 11, 2021: Venus and Mars to Do-Si-Do

During this past week, I have had the pleasure of watching Venus, the Goddess of Beauty, approach Mars, the God of War, in the early evening western sky about 45 minutes after sunset. If I were into astrology, this might be a good time to be born. Or not, because there is another woman hanging around, Diana the Moon Goddess. • Venus is pulling away from the sun and will become more prominent in the early evening sky during the next month, but it will never achieve distinction because of its low altitude. Mars, on the other hand, has been in our sky for the past 12 months, achieving celebrity last year during late summer and throughout the autumn months when it was near the Earth and rivaled Jupiter in brightness. It has been in a losing battle with the sun ever since, as is the fate of all of the planets we observe in the sky. The sun will eventually catch up to and pass Mars on October 8, forcing the Red Planet into the morning sky until its next opposition to Earth on December 13, 2022. • These two planets are in for a little do-si-do during the next several days. On July 11, forty-five minutes after sundown, Venus and Mars will be found in the WNW, separated by only one degree and about eight degrees above the horizon. That is a little more than one binocular field of view. Mars will be to the left of Venus about as bright as the brightest stars of the Big Dipper while Venus will only be dwarfed in reflected luminescence by the moon to its right. Luna will be a razor thin crescent with only four percent of its disk in sunlight. Because of their closeness to the horizon, I strongly recommend having binoculars or a spotting scope with you, particularly to see Mars. • Use your binoculars to see the old moon in the new moon’s arms. This is really earthshine, the reflected light from the Earth, returned back to our planet from the moon. If the earthshine is vibrant, the portion of the moon that is not in sunlight will appear to glow feebly. • Keep in mind that when the moon appears as a thin crescent, the Earth, as seen from the nearside of the moon, is virtually full, providing about 80 times the amount of illumination that we receive from Luna when it is in its full phase. If you don’t have binoculars, try using averted (side) vision to spot earthshine. In other words, look away from the moon, then use your side vision to look at Luna. You can use the same techniques with binoculars to enhance the effects of earthshine. • By the 12th the moon has moved above the pair and is nine percent sunlit, but with plenty of earthshine still visible if the weather conditions are transparent enough. Venus too has moved to a position slightly above Mars, but their separation has now decreased to only one-half degree, the angular diameter of the moon. The three objects should be a tight fit in the same field of view for most regular binoculars as they were the previous evening. By Tuesday, July 13, Venus stands directly over Mars clearly in the lead, but still only a half degree apart. It is actually closest on this evening. Wednesday sees the separation of Mars and Venus increase to one degree, still very near for a conjunction of two planets. By Wednesday, July 21, Venus is only a degree from the first magnitude star Regulus of Leo the Lion, and still only five degrees from Mars, creating another very fine binocular view. Keep looking upwards and follow your star! Ad Astra!

1300 July 18, 2021: Madhouse at the End of the Earth: An old adage to the secret of happiness goes like this—something to do, someone to love, and something to look forward to. I have found it a wonderful axiom in monitoring my feelings of contentment. It also fits well with writer Julian Sancton’s vivid portrayal regarding the difficulties of spending a year in captivity on the frozen pack ice that befell the officers and crew aboard the Belgica, the ship that carried the Belgium Antarctic Expedition to the Bellingshausen Sea in 1897. Sancton’s exhaustively researched book, Madhouse at the End of the Earth, Crown, 2021, documents the rapid deterioration of the Belgica’s crew and officers after being enmeshed by the ice and the bitter cold of an Antarctic winter. With very little to keep the seafarers occupied, the monotony of a long winter’s night, canned food that was tasteless and gelatinous in texture, an abundance of shipboard rats, and the daily uncertainty of the Belgica being crushed by pack ice, the crew and some of the officers rapidly sank into a state of lethargy, despair, and mental exhaustion. • NASA has studied the plight of the Belgica in the hopes of providing additional context to the human exploration of Mars. According to one scenario, it will require at least nine months outbound and perhaps as little as six months to return to the Earth. Throughout the duration of their journey, four to six astronauts will set up housekeeping in exceptionally cramped quarters, with little privacy, little to occupy their time while in transit, and little to look forward to until they reach Mars. In addition, space travel is dangerous and unforgiving with mistakes and accidents easily resulting in death. The question that many experts have asked is how do you prepare a crew for the anxiety, physical inactivity, and boredom that may result in such a long voyage? • The Belgium Antarctic Expedition may provide some answers. It was organized and commanded by naval officer, Adrien de Gerlache, who was a more than capable seaman but much less of a leader. The multilingual, multinational crew continuously chaffed with one another to the detriment of a well-functioning vessel. In contrast to de Gerlache’s weakness as a commander, American polar explorer and ship’s doctor, Frederick Cook, and the Norwegian polar explorer, Roald Amundsen, were respected by everyone. Amundsen would be the first to cross the Northwest Passage as well as to conquer the South Pole. • Cook and Amundsen became close friends, feeding off each other’s desire to continue their polar explorations after the Belgica safely returned to Antwerp, staying mentally and physically active, and devising new equipment and strategies for cold weather survival. Both Cook and Amundsen remained in good health throughout most of their captivity on the ice, but the rest of the crew and officers did not. As the sailors descended into a scurvy-induced stupor, Cook introduced light therapy, having the men stand naked in front of a roaring fire. He insisted on everyone exercising and eating fresh penguin meat and seal when it was available, but not all of the men, including de Gerlache complied. Three other Belgium sailors also refused Cook’s advice, subsisting only on the ship’s rations. Their conditions did not improve. I found this a compelling parallel to the present resistance surrounding science and receiving the COVID vaccination, even though it is highly evident that those individuals who have been inoculated are faring far better than those people who have stubbornly refused treatment. • Eventually, all of the men on the Belgica did conform. Along with fresh meat and a regimen of rigorous exercise, as the men tried to saw their way through the ice to freedom, the health of the crew improved greatly. Hopefully, on the first voyage to Mars there will be modern versions of Frederick Cook and Roald Amundsen onboard to help to guide the crew safely to the Red World and keep the physical and mental states of these “New World” explorers in balance.

1301 July 25, 2021: Jupiter and Saturn at Opposition: Remember when last December, Jupiter and Saturn were nearly hugging each other in the southwestern sky after sundown? They were in conjunction—together, but not forever as faster moving Jupiter caught up to and passed Saturn on December 21. Six weeks later, the sun caught up to the pair, passing slower moving Saturn on January 23, and Jupiter just five days later. After these two rapid fire and invisible conjunctions, the sun moved eastward on its annual circuit of the sky. Jupiter and Saturn were conscripted into becoming morning planets, rising before the sun rose, forgotten by most people except for the earliest risers who saw monthly a thin crescent moon tangling with the pair. • Gradually, the sun moved farther and farther away from these two worlds, creating another interesting geometric configuration called quadrature, where the sun and the planet as viewed from the Earth were 90 degrees apart from each other. Saturn was at quadrature on May 3 of this year. Since Jupiter was leading Saturn, it took longer for Jove. It attained quadrature nearly three weeks later on May 21. Since both Jupiter and Saturn were west (left) of the sun, this specific planetary configuration is called a western quadrature. The planet rises at midnight, is due south at sunrise, and sets at noon. • The gap between Jupiter, Saturn, and the sun has continued to widen over the past several months. On August 2 for Saturn and August 19 for Jupiter, the sun will be 180 degrees apart from these planets at a location called opposition. The planets will be visible all night long, rising when the sun sets in the evening, and setting when the sun rises the following morning. At local midnight (1 a.m. for daylight saving time) the planets will be due south and highest in the heavens. • In order for an opposition to happen, the Earth must be between the sun and the planet, meaning that not only is the planet visible for the entire night, but it is also closest to the Earth, the time when the planet is brightest and the best time to view it through a telescope. After opposition, the sun starts gaining on the planets, closing the gap until they are once again 90 degrees apart, this time at eastern quadrature and months later in conjunction with the sun. • This series of geometric arrangements, except for the moon, is specific to (superior) planets and other astronomical bodies that are farther away from the sun than the Earth. For the faster moving moon, conjunction corresponds to a new moon, when the moon is between the Earth and the sun and its nearside is in darkness. Eastern quadrature happens when the moon is positioned 90 degrees to the east of the sun at its first quarter phase, half on, half off with its light to the right. Full moon arises when Luna is opposite to Sol, at opposition, with the Earth between the sun and the moon. Finally, last quarter transpires when Luna is at western quadrature, half on, half off, but this time with its light to the left. • The moon was at opposition (full) on July 23 and will be at western quadrature (last quarter) on July 31. As for Jupiter and Saturn, check them out low in the southeast around 11 p.m. this week. Jupiter will be the brighter of the pair and to Saturn’s left. Ad Astra!