Mon Mar 11, 2024 WHY DOESN’T POLARIS MOVE?
Earth’s north pole points toward the star Polaris. As the earth rotates, stars rise out of the east and set in the west. But Polaris doesn’t move. It’s like spinning a basketball. There’s only one other place to put a second finger on the ball and not disrupt rotation, and that’s the top of the ball. Now think of standing on the top of the earth. Look straight up. Instead of a giant finger, you’ll see a star. That’s Polaris, and it appears on the zenith, 90 degrees overhead, from the Earth’s north pole, which is at 90 degrees North latitude. If you slide down the Earth, then the North Star slides downward: at 45 degrees North latitude, Polaris is halfway up the north sky. But if you go to the equator, 0 degrees, then Polaris is on the north horizon, and you can’t see it.
Tue Mar 12, 2024 SUN, SOLAR YEAR AND ECLIPTIC
Watch the sun and you’ll discover it gets around. But of course you can’t watch the sun - it’s too bright to look at without hurting your eyes. Assuming you could see the sun and stars at the same time, you’d notice the sun drifts against the background of the stars. If we think of the stars as being laid out on an invisible sphere, and there are 360 degrees of angle on a line inscribed on that sphere, then the sun moves along that line almost 1 degree a day. After 365 days, the sun would be back where it started. A solar year, then is the amount of time it takes the sun to go once around the heavens, and that invisible line that traces out its path is called the ecliptic. The constellations through which the sun passes each year make up the zodiac, and the ecliptic is its central line.
Wed Mar 13, 2024 URANUS AND PLUTO DISCOVERIES
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.
Thu Mar 14, 2024 NAME THAT CONSTELLATION – MARCH
Can you identify the thirty-ninth largest constellation? It is bordered on the north by Triangulum and Perseus, on the south by Pisces, Cetus the Whale and Taurus, on the west by Pisces again, and on the east by Taurus again. Three middling-bright stars – Hamal, Sheratan and Mesarthim, form its head, however the rest of this constellation is in one of the darkest regions of the night sky, and there are no famous nebulas or star clusters within its borders. But a handful of its stars are known to have planets orbiting them. In mythology this animal represents the golden fleece, sought by Jason and his Argonauts. Tonight the crescent moon and the planet Jupiter can be found within its borders. Can you name this, the first constellation of the Zodiac? The answer is Aries the Ram, in the southwestern sky after sunset.
Fri Mar 15, 2024 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.
