Skywatch for the week of 3-13-2023
Mon Mar 13, 2023 URANUS DISCOVERED/PLUTO DISCOVERY ANNOUNCEMENT
On March 13, 1781, the planet Uranus was discovered by William Herschel. Using a telescope he had built himself, Herschel 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 this, Arizona’s Lowell Observatory announced the discovery of another planet. It had been found by a young observatory assistant, Clyde Tombaugh, and was named Pluto. In 2006 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 2015 the New Horizons space probe flew past Pluto and radioed back some incredible images of this distant world and its moons.
Tue Mar 14, 2023 WILLIAM CHALONER – EXECUTED BY NEWTON
On March 16th, 1699 William Chaloner was executed at Tyburn Tree in London. Before his gruesome death, he wrote a letter to Sir Isaac Newton, begging for his life. “O dear sir, no body can save me but you,” he wrote, “I shall be murdered unless you save me.” Newton, England’s greatest scientist, had recently become the warden of the mint, and was responsible for the coining of English currency. This included catching counterfeiters. Chaloner accused Newton of incompetence and corruption. This did not please Newton, and he set out to catch the great counterfeiter. Like a 17th century Sherlock Holmes, Sir Isaac used informers and even went about in disguise to find out what Chaloner was up to. In this way, the man who gave us the laws of gravity and motion gathered enough evidence to send Chaloner to the gallows.
Wed Mar 15, 2023 CAESAR AND THE IDES OF MARCH
Today is the Ides of March, that is, March 15th. On this day in 44 BC Julius Caesar was assassinated, and we think of Shakespeare’s play, in which Caesar is 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, marked by the new moon, was called the Kalends (from which we get the word calendar;) A week later the first quarter moon and the Nones; 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 16, 2023 ROBERT GODDARD’S ROCKET
Nearly a hundred years ago, the world’s first liquid-fueled rocket was launched, by Robert Goddard, who invented it. 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 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 17, 2023 SAINT PATRICK ASTRONOMY
On this Saint Patrick’s Day, let’s talk about the astronomy of medieval Ireland. In the fifth century the Irish used stone circles that, like the famous Stonehenge of England, could predict sunrise and sunset positions and the beginnings of seasons. The early Church relied on Irish astronomers to help establish the dates of Easter and other religious feasts, as witnessed by the sixth century Irish monks. The 7th century 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 Polaris, the North Star was called an Gaelin, the light that brings you home.