Skywatch for the week of August 3, 2020
Mon Aug 3, 2020 FULL AUGUST MOON
The moon is full today. This evening, it will be found among the stars of the constellation Capricornus. To the west of the moon you’ll also notice two bright stars: the first star has a slightly yellow color and is actually the planet Saturn, while the much brighter star that’s farther to the west is the planet Jupiter. Colonial Americans knew August’s full moon as the Dog Days moon; ancient Celts called it the Dispute Moon. The Sioux Indians say that this is the Moon When the Geese Shed Their Feathers. The Ponca call it the Corn is in the Silk Moon, meaning it's a good time to harvest the corn; other tribes have similar names, such as the Big Ripening Moon of the Creek and Seminole Indians or the even more simply named Corn Moon of the Zuni. To the Cherokee, though, this is the Drying Up Moon, appropriate after a long hot spell of summer weather.
Tue Aug 4, 2020 MARIA MITCHELL
The first American woman astronomer, Maria Mitchell, was born on August 1st in the year 1818. She learned astronomy from her father William Mitchell; as a young girl she helped him in his observatory on Nantucket Island. And on October 1st, 1847 she set up a telescope on her parent’s housetop and discovered a comet. The next year she became the first woman member of the American Academy of Arts and Sciences. She also served as professor of astronomy at Vassar College from 1865 until a year before her death in 1889. She contributed to the American Nautical Almanac, observed sunspots and solar eclipses, plus the planets and the moon. A crater on the moon is named for her. Maria Mitchell said, “We especially need imagination in science. It is not all mathematics, nor all logic, but is somewhat beauty and poetry.” But she also asked of her students, "Did you learn that from a book or did you observe it yourself?"
Wed Aug 5, 2020 QUASAR DISCOVERY
The first quasar was discovered on August 5th, 1962. It has the unromantic designation, 3C273, the 273rd object in the third Cambridge catalog of radio sources. Quasi-stellar radio sources, or quasars, are so faint they can only be seen by powerful telescopes. They look like stars, but quasars emit a lot of energy in other wavelengths of light invisible to the human eye. They’re dim because they’re really far away! 3C273 actually puts out more energy than the combined light of the hundreds of billions of stars of our entire Milky Way, and this from an object only the size of our solar system! We think quasars are the hearts of galaxies that formed when the universe was young; these powerful light sources no longer exist. 3C273 is in our southwestern sky this evening, not too far from the bright star Spica in the constellation Virgo,(but several billion light years farther out of course.)
Thu Aug 6, 2020 MOON AND MARS
The moon is just a few days past full, and is now called an old gibbous moon or a waning gibbous moon. Tonight it rises in the late evening, and is among the stars of the constellation Pisces the Fish. By tomorrow night – that’s Friday night, because it’s traveling in an orbit around us, the moon will still be in Pisces, but about thirteen degrees farther to the east. You can measure this change with your hand. Just hold your hand out at arm’s length, fingers together, and place the edge of your hand along the east side of the moon. The next night, the moon will have gone all the way over to the other edge of your hand. On Friday night, repeat this measurement, and you should notice that along the east edge of your hand, there’s a bright, red-tinged star, which happens to be the planet Mars. On Saturday night, the moon and Mars will appear to be right next to each other!
Fri Aug 7, 2020 GALILEO’S FIRST TELESCOPE
On August 8th in the year 1609, members of the Venetian senate climbed to the top of the tower of St. Mark’s Cathedral for a demonstration of Galileo’s first telescope. The senators viewed ships far out at sea, ships that couldn’t be seen by the naked eye for another two hours. What a marvelous invention! Galileo’s salary as professor of mathematics at the University of Padua was immediately doubled. Now if you were to buy today the cheapest, crummiest telescope you could find, it would still be vastly superior to that first one. Galileo did not invent the telescope; he had simply been told about telescopes built by others, and made one of his own based on the reports. But it was what he did with the telescope that made the difference. Instead of looking at ships out at sea, he turned the telescope skyward, and wrote about the moon, the planets and the stars - all the marvelous sights visible in the heavens.