Mon June 3, 2024 NORSE STAR PATTERNS
An old Norse story said that the earth was fashioned from the great body of the giant Ymir. Norse star patterns were also different from those we know today. The Big Dipper, now upside down in the north after sunset, is part of the great bear Ursa Major. But to the Norse, the Big Dipper was called Odin’s Wagon. This wagon or chariot must have been a pretty good ride, because it was passed down to Odin’s son Thor; and Ursa Minor, the Little Bear, also called the Little Dipper, was driven by Freya, Thor’s wife, the Norse goddess of love. Thor himself may be represented by the constellation Orion, right down on the west horizon at sunset this evening, while the brilliant star Sirius, to the east of Orion, was called Loki’s flaming torch, and whenever it flashed and twinkled, the Norse said that Thor’s brother was working great mischief in the halls of Asgard.
Tue June 4, 2024 THE BRIGHTEST STARS ARE RAREST
This evening you’ll notice the bright stars first. 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 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.
Wed June 5, 2024 JOHN COUCH ADAMS
John Couch Adams, born on June 5th,1819, was the first to predict the location of Neptune. Astronomers noticed that Uranus, thought at the time to be the outermost planet, did not follow its predicted path. The gravity of some massive object farther out was pulling on it, altering its orbit. In 1845, Adams deduced the location of the hidden gravity source, and in 1846, Neptune was discovered telescopically by J.G. Galle; but Galle had never heard of Adams! Galle used the predictions of the French mathematician Jean Leverrier instead, who had also arrived at a solution to the orbit problem a year after Adams. But Adams had sent his calculations to the Astronomer Royal, George Airy, who did nothing with the information because Adams had not shown all his work and didn’t follow through with Airy’s request for more information and never made an appointment to talk to him about it – definitely a failure to communicate.
Thu June 6, 2024 STAR TRAILS: AS THE WORLD TURNS
An elegant demonstration of the earth’s rotation is the motion of the stars across the heavens as the night progresses. A camera attached to a tripod with the shutter left open can record the movement of the stars as they rise and set. The result will be a photograph that shows star trails. Aim your camera east or west and you can get star trail lines that appear as diagonal streaks across the picture. Aim your camera south and you’ll get star trails that bend in broad, curving arcs that run along the southern horizon. But aim your camera north, with the star Polaris in the center of the viewfinder, and you’ll get star trails that move in nested circles around the North Celestial Pole. Even Polaris, the North Star, will show a very slight movement, as it is displaced from the earth’s pole by just under a single degree of angle.
Fri June 7, 2024 GIOVANNI CASSINI
The 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 went into orbit around Saturn in 2004. If you want to see Saturn tonight, it will be rising in the east an hour or so before dawn, in the constellation Aquarius. But you won’t be able to find the Cassini spacecraft – it plunged into the ringed planet back in 2017.