Skywatch for the week of December 30 , 2019
Mon Dec 30, 2019 SIR ARTHUR EDDINGTON
Sir Arthur Eddington was born on December 28, 1882. It was Eddington who proved Einstein’s theory of general relativity. He was a great scientist, and he knew it. When someone praised him as being one of only three people who understood Einstein’s theory, he replied, “Well, there’s me, and there’s Einstein. Who else is there?” Einstein’s theory of general relativity said that the gravity of a massive object, like the sun, could bend any light waves that came near it. So any stars that were along the same line-of-sight as the sun would seem displaced by its gravity. You can’t ordinarily see stars near the sun, because it’s too bright. But during a total solar eclipse, you can. And during a solar eclipse in 1919, observations by Eddington found that stars near the sun in Taurus, a constellation that’s visible in our southern sky this evening, were displaced – he had proved Einstein’s theory.
Tue Dec 31, 2019 NEW YEAR’S AVATAR
Often the outgoing year is portrayed as a very old man known as Father Time. Father Time in turn is based on the Greek mythological god Kronos, whom the Romans associated with Saturn, an agricultural god. The planet Saturn takes 29 years to orbit the sun, so to sky-watchers of long ago, it seemed as if this slow-moving, unhurried planet must somehow be associated with time. In late December great festivals like the Saturnalia were held in honor of Saturn. Gifts were exchanged, homes and streets were decorated, and everybody was in a happy party mood. After this came the solstice and celebrations of the sun, then another holiday for Janus, the Roman god of new beginnings, and for whom the month of January is named. If you want to see Saturn tonight, you’ll have to look just after sunset: it’s on the southwestern horizon, above the glow of sunset.
Wed Jan 1, 2020 JANUARY AND THE NEW YEAR
January is named for Janus, the Roman god who had two faces: one looked back to the past, the other looked forward to the future. This is also now the year Two Thousand and Twenty, which according to the calculations of a Roman monk, Dionysius Exiguus, marks the two thousand and twentieth year following the birth of Christ – AD – Anno Domini – in the year of Our Lord - 2020. But Dionysius’s count was off by one year. Our calendar goes from 1 BC to AD 1 – there is no zero year, because the numerical concept of zero was not used back then. But why does the new year start today? There's nothing astronomically special about this time; and astronomers are the ones who invented calendars. Before 1751, New Year's in America began on March 25th, the beginning of spring. It’s also been observed at the beginning of summer, or during the autumn harvest. Well, no matter how you reckon time, the earth just keeps on rolling along.
Thu Jan 2, 2020 SKYWATCH 25
Skywatch was first broadcast twenty-five years ago today, on January 2nd, 1995. Before I came to Indian River State College I did similar programs on WGH and WHRO radio in Tidewater, Virginia for about fourteen years. And in the two years before that, I handled the telephone sky information service at the American Museum of Natural History’s Hayden Planetarium in New York. So over the years, I’ve developed a list that helps me decide what to talk about. Highest priority goes to current sky events - eclipses and meteor showers, comet apparitions, pretty conjunctions of the moon with bright stars and planets, and the changes of the seasons, as well as any breaking news in astronomy. Next come any historical events such as discovery dates and the births and deaths of famous astronomers. After that I tell folks about stars and constellations they can see in the current evening sky. And finally, I talk about astronomy concepts and general sky phenomena.
Fri Jan 3, 2020 NAME THAT CONSTELLATION – JANUARY!
Can you identify the 14th largest constellation in the sky? It is bordered on the north by Pegasus, Andromeda, Triangulum and Aries; on the south by Aquarius the Water Carrier and Cetus the Whale; on the west by Pegasus and Aquarius again; and on the east by Triangulum, Aries and Cetus again. There are no bright stars in it, but within its borders is M74, a beautiful spiral galaxy seen face-on, that’s a little over 20 million light years away. This mythological figure is said to represent the goddess Venus and her son Cupid, who transformed themselves in order to swim away from a dangerous dragon. The waxing crescent moon can be found within its borders this evening, beside one of the two fish in this star pattern. Can you name this star figure, the twelfth constellation of the zodiac? And of course the answer is Pisces, the Fish, well-placed in the southwestern sky after sunset.