Skywatch week of 3-25-2019
Mon Mar 25, 2019 ROBERT FROST
Robert Frost was born on March 26th, 1874. In his poem, "The Star Splitter." Frost relates the tale of a man who bought a telescope, saying "The best thing that we're put here for's to see; The strongest thing that's given us to see with's A telescope. Often he bid me - come and have a look - Up the brass barrel, velvet black inside, At a star quaking in the other end. That telescope was christened the Star-Splitter, Because it didn't do a thing but split A star in two or three...” Frost was referring to the telescope’s ability to resolve detail, and reveal fainter stars not visible to the human eye alone. In another poem, Frost describes the constellation Canis Major, the “great Overdog That heavenly beast With a star in one eye Gives a leap in the east. He dances upright All the way to the west And never once drops On his forefeet to rest.” Because of the earth’s rotation, Canis Major does move across the sky just the way Frost describes it.
Tue Mar 26, 2019 SEASONAL CONSTELLATIONS/ASTRONOMY CLUB MEETING
With the new season of Spring underway we find that Winter constellations like Orion the Hunter, Taurus the Bull, the Big and Little Dogs, Auriga the Charioteer and the Gemini Twins have slipped over into the western evening’s sky, as new star groups take their places in the heavens above. Leo the Lion and the Big Dipper appear above the eastern and northeastern horizon after sunset; and soon the bright stars Arcturus and Spica will rise. If you want to keep up-to-date with sky events like this, there is a great local astronomy club that can help: it’s called the Treasure Coast Astronomical Society, and in addition to having star parties and sky watching events for their members, the club is also open to the public. The TCAS will have its monthly meeting tonight at 7:30 pm at the Science Center Auditorium, that’s in the N building, on the main Fort Pierce campus of Indian River State College, and it’s free.
Wed Mar 27, 2019 CHANGES IN LATITUDE, CHANGES IN DAYLIGHT
The times of sunset and sunrise change from day to day, but they also change as you move north or south. Near the equator, day and night are fairly equal in length throughout the year; but as you head toward the poles, the daylight and darkness periods around the beginnings of summer or winter become extreme. Most places on earth experience long daylight periods with short nights in the summer months, and short daylight periods and long nights in the winter. This is caused by the earth’s tilt as it travels around the sun. A lot of us have a mental picture of the earth flopping over from one side to the other as it moves in its orbit, but that’s not the case. It’s more like watching a steady gyroscope, with the axis of rotation pointed always in one direction, and that direction, the spot in the sky where the earth’s north pole is aimed, is toward the star Polaris, more commonly called the North Star.
Thu Mar 28, 2019 SUN, SOLAR YEAR AND ECLIPTIC
Watch the sun and you’ll discover it gets around. But of course you can’t watch the sun, because it’s too bright to look at without hurting your eyes. If you could somehow dim down the sun enough, you could also see the stars in the sky at the same time. (Actually, there are times when this happens – during total solar eclipses.)Assuming you could see the sun and stars at the same time, you’d notice the sun drifts eastward like the moon, although not as fast as the moon. The moon moves 13 degrees a day; the sun only moves about 1 degree a day. After 365 days, the sun would return to conjunction with the star it had been beside exactly a year ago. A solar year, then is the amount of time it takes the sun to go once around the heavens, and the invisible line that traces out that path is called the ecliptic. The constellations through which the sun passes each year is called the zodiac, and the ecliptic is its central line.
Fri Mar 29, 2019 OUT WITH THE RAM
March comes in like a lion and goes out like a lamb. This saying is meant to refer to the improving weather in the springtime of the year. But there is also an astronomical connection. At the beginning of March, the constellation Leo the Lion makes its way into the evening sky, appearing in the east after sunset. As the month progresses, Leo appears a little higher in the sky each night, while in the west, many constellations of the late fall and early winter are sinking toward the horizon. By the end of March, one of our winter constellations makes its exit in the western sky. For the past few weeks, the sun has been steadily encroaching on this constellation, as the earth’s revolution has caused the sun to slowly slip eastwards against the background of distant stars. Now the sun is about to pass between us and the constellation Aries the Ram. March comes in with the Lion and goes out with the Ram.