Skywatch week of March 11, 2019
Mon Mar 11, 2019 PLACES IN THE SKY – MARCH
Of the eighty-eight officially recognized constellations, can you identify the seventeenth largest one? It is bordered on the north by Auriga and Perseus, on the south by Eridanus, on the west by Aries, and on the east by Orion. Within its borders are such deep sky objects as the Crab nebula, the Hyades star cluster, and the better-known Pleiades, or Seven Sisters. This constellation’s brightest star is Aldebaran, a red giant forty times larger than the sun. One of the oldest star patterns, in mythology this animal is sometimes seen as a representation of Zeus, who carried the princess Europa across the sea to Crete; or as the seventh labor of Hercules; and tonight the new crescent moon and the planet Mars are together on its western border. Can you name this star figure, the second constellation of the zodiac? The answer is Taurus the Bull, currently visible high in the southern sky this evening.
Tue Mar 12, 2019 URANUS DISCOVERED/PLUTO DISCOVERY ANNOUNCEMENT
On March 13, 1781, the planet Uranus was discovered by William Herschel. Herschel was a church organist and music director in the city of Bath, England. But he dabbled in other pursuits, and astronomy was his passion. Using a telescope he had built himself, he became the first person in history to discover another planet too faint to be seen with the unaided eye. About a hundred and fifty years after Uranus was discovered, the Lowell Observatory in Arizona announced the discovery of another planet. It had been found by a young observatory assistant, Clyde Tombaugh, and was named Pluto. Several years ago an international group of astronomers who had nothing better to do with their time voted to demote Pluto to dwarf planet status, but the American Astronomical Society opposes the idea. In the summer of 2015 a space probe named New Horizons flew past Pluto and radioed back some incredible images of this distant world and its moons.
Wed Mar 13, 2019 CAESAR AND THE IDES OF MARCH
We’re coming up on the Ides of March, and it looks like this time around no Roman dictators will be killed. On March 15th in 44 BC Julius Caesar was assassinated, and many of us remember Shakespeare’s play, Julius Caesar, in which he was warned to beware the Ides of March. What are the Ides? The Romans divided their calendar month into three parts, with three specific days serving as benchmarks, based on the phases of the moon. The first day of the month was marked by the new moon and was called the Kalends (from which we get the word calendar;) A week later came the Nones, marked by the first quarter moon – and you can tell we don’t use a lunar calendar anymore because the moon is a waxing crescent today; and the middle of the month, the 13th day or in some cases the 15th, when the moon was full - that was the Ides. These terms are not familiar to us today, but they were well-known to the Romans, and also to Europeans in Shakespeare’s time.
Thu Mar 14, 2019 ROBERT GODDARD’S ROCKET
Ninety-three years ago, the world’s first liquid-fueled rocket was launched, in Auburn, Massachusetts. The man who launched it was its inventor - Robert Goddard. Rockets had been around for a long time – the Chinese were using them eight hundred years ago. But all rockets up to March 16, 1926, were solid-fuel, using a kind of gunpowder as the propellant. The problem with those rockets was that once ignited, the rocket fuel continued to burn until it was used up – no off switch. With liquid fuel it was possible to start, stop, restart, throttle the engine up or down - in other words, liquid-fueled rockets were easier to control, and safer too. The folks in Massachusetts didn’t seem to appreciate this however, and he was branded a nuisance. And the New York Times back then said he was wrong, that rockets wouldn’t work in space. Evidently they were mistaken, because, thanks to Robert Goddard, we’ve sent rockets outward to the moon, to the planets, to the stars.
Fri Mar 15, 2019 SAINT PATRICK ASTRONOMY
This Sunday is Saint Patrick’s Day, so let’s talk about Irish astronomy as it was practiced in the time of the Saint. In the fifth century the Irish made accurate observations, using stone circles that, like the famous Stonehenge of England, could predict sunrise and sunset positions and the beginnings of seasons. The Julian calendar of Rome was used in Ireland, and the Church relied on Irish astronomy to help establish the dates of Easter and other religious feasts, as witnessed by the Sixth century abbot, Mo-Sinu maccu Min of County Down. In the Seventh Century the monk Aibhistin suggested a connection between the tides and the phases of the moon. And then there are the Celtic constellations: Leo the lion which appears in the east after sunset, was An Corran, a sickle or reaping hook. The Irish saw Orion the Hunter as the hero Caomai, the Armed King. And the Milky Way was called Bealach na Bo Finne - the way of the white cow.