Skywatch for the week of June 7, 2021
Mon June 7, 2021 PLANET SYMBOLS
Some star charts locate the positions of the moving planets, often using a symbol instead of the actual name. Each symbol is based on some aspect of that planet. Mercury, the messenger of the gods, has a walking stick symbol with two snakes wrapped around it (Yeah, that’d make me walk faster too.) A circle on a letter t makes a hand mirror - that’s for beautiful Venus. Mars, god of war, is symbolized by a shield and a spear. A stylized lightning bolt is the symbol for Jupiter, ruler of the sky. Saturn, god of the harvest, has a scythe. For Uranus, it looks like somebody jammed a Mars symbol onto a sun symbol; it’s probably got something to do with sex, but this isn’t that kind of a program so let’s move on. The moon’s symbol is the best, it looks like a crescent moon, while the sun is a dot inside a circle, like a drawing of an orbit around a star. Neptune is the king of the sea, so he bears a trident; and Pluto's is "P" and "L" combined. Can we talk about Pluto as a planet? Well, it’s got a symbol, so, yes!
Tue June 8, 2021 GIOVANNI CASSINI
The great astronomer Giovanni Cassini was born on June 8th, 1625. In 1665, he made the first detailed observations of Jupiter’s Great Red Spot, an immense 400 mile-an-hour storm a couple of times larger than earth. Ten years after that, he discovered a gap about two-thirds of the way out in Saturn’s ring system, something we now call the Cassini Division. Saturn’s rings are made up of billions of tiny moonlets of water ice, ranging in size from icebergs down to fist-sized and smaller particles. The gap that Cassini discovered is something of an illusion - there are ice chunks there, just not quite as plentiful as elsewhere. A spacecraft named for the astronomer orbited Saturn from 2004 until it was destroyed in 2017. In the weeks to come we’ll have really nice views of Saturn, along with Jupiter, over between the constellations Sagittarius and Capricornus, in the southeast beginning in the late evening hours after sunset. Saturn is the fainter star to the west.
Wed June 9, 2021 IROQUOIS CREATION MYTH
In an old Iroquois story, the world began long ago when the great tree of light was plucked out of the ground of heaven, and Ataensic, the sky woman, who was wife to earth-holder, came down to the world below. Now at that time there was no land, only water as far as the eye could see. The birds of the air and the creatures of the water came together in council to decide where Ataensic would live. The mud turtle was the best of all the animals for supporting the woman above the water, as he could swim without tiring, and sky woman was set down on his shell. The others brought gravel and mud up from the bottom to place upon the turtle's back; and the land grew. Sky woman planted seeds from the great tree of light, so that the earth became a green place too. Now Ataensic’s daughter had two sons: the Great Spirit, Mannitto, and the Evil Spirit. From his mother’s face the Great Spirit made the sun; and from her body he made the moon and stars in the sky. And so it has been to this day.
Thu June 10, 2021 ORION ON THE RUN
Orion the Hunter, which has dominated our evening skies since winter, is about to disappear. Tonight he rests on the western horizon at dusk. But in the next couple of weeks, as the earth moves to a point in its orbit where the stars of Orion will drift behind the sun, we will lose sight of it until it reappears in July, rising out of the east before dawn. An old myth says it’s because of the arrival of the constellation Scorpius, which is on the opposite side of the sky from the hunter. Twenty-three hundred years ago, the poet Aratus wrote, "tis said that when the Scorpion comes, Orion flees to the utmost ends of the earth." You see, Orion once boasted that no animal on earth could hurt him. That kind of talk invariably leads to disaster, and sure enough, a scorpion rose up from the ground and stung Orion. The dying hero was given new life as a constellation, but he still fears the scorpion, for whenever Scorpius rises out of the east, Orion ducks down below the west horizon.
Fri June 11, 2021 THE BRIGHTEST STARS ARE RAREST
When you look at the sky this evening, the first thing you notice are the bright stars, called first magnitude stars since they’re the brightest. These 1st magnitude stars, like the blue giant star Spica in the constellation Virgo, and the red giant star Arcturus in the constellation Boötes, or other giant stars such as Sirius and Procyon, in the Big and Little Dogs, or Castor and Pollux in Gemini, are scattered about the sky, and it would seem that these giant stars are fairly common. But the giant stars are actually quite rare. The most common of stars in our galaxy are red dwarfs, and because they’re so small and cool, they’re not visible to the unaided human eye. Barnard’s Star, which rises out of the east in mid-evening, is a typical red dwarf. But unless you have a pretty good telescope and know just exactly where to look for it, you’ll never see Barnard’s Star, which is just under six light years, or 35 trillion miles away, almost a next-door neighbor, cosmically speaking.