Skywatch for the week of Julyt 26, 2021
Mon Jul 26, 2021 THOMAS HARRIOT BEATS GALILEO
Toward the end of July in the year 1609, the Englishman Thomas Harriot made the first really good drawings of the moon as seen through a telescope. Galileo would make his drawings several months later, less detailed and accurate than Harriot’s, but while Galileo’s fame has continued through to the present day, hardly anyone has ever heard of Harriot. Galileo published his discoveries in his book, the Starry Messenger. Harriot on the other hand, put the bulk of his work in manuscript form, but never published an actual book for public consumption. Harriot led an interesting life, accompanying Sir Walter Raleigh to the Roanoke colony in America, serving as mathematician, navigator and interpreter. He was briefly imprisoned in 1605 on account of suspicions that he had been part of the assassination attempt on King James 1. He was innocent and released, but this may have made him less eager to publish, not wishing to draw attention to himself.
Tue Jul 27, 2021 SUN IN LEO? NO, CANCER!
Most folks know their astrological sun sign; it's supposed to tell you where the sun was in relation to the zodiacal constellations on the day you were born. So if you're a Leo, say, that means the sun was in that part of the sky where you’d find the stars of Leo. Now you can't see Leo at that time, the sun is in the way. According to astrologers, if you were born between July 23rd and August 22nd, then you are a Leo - bold and courageous, and your personality embodies the noble qualities of the beastly lion. Well, this all sounds great, but the problem is that the sun isn’t really in Leo right now, it’s in Cancer, so I guess that means you’re really a crab. Thousands of years ago when astrology was concocted, the sun would have been in Leo, but thanks to the earth's slow precessional wobble on its axis, all the zodiacal figures have shifted over by one constellation, turning lions into crabs, centaurs into scorpions, and bulls into sheep.
Wed Jul 28, 2021 THE DOG DAYS
These are the "dog days" of summer. The sun was highest in our noon sky on June 21st, but it takes the air a month to really sizzle. We call these the dog days because it's at this time of the year that you can first catch sight of the brilliant star Sirius, also known as the Dog Star, low in the southeast, rising just before the sun. Sirius is the brightest star in the night sky, partly because it’s a big, hot star, but mainly because it’s closer to us than most other stars, only about 54 trillion miles away! Its name is from the Greek word, "seirios," which means, “sparkling,” or “the scorcher.” Sirius is in the constellation Canis Major, the Big Dog – it usually marks the dog’s nose – and that’s why we also call it the Dog Star. Sirius was feared and hated by the ancient Greeks and the Romans, who thought that when the sun and Sirius got together, their combined heat burned up the crops, made dogs go mad, and generally caused a lot of discomfort for everybody else.
Thu Jul 29, 2021 DELTA AQUARID METEOR SHOWER
A meteor shower is going on right now. It’s called the Delta Aquarid meteor shower, so named because these meteors come out of the constellation Aquarius, near its fourth brightest star, Delta Aquarii. Most meteor showers are caused by tiny bits of comet dust in space. As the dust hits the earth’s upper atmosphere, it vaporizes, which then heats the air the dust passes through, lighting it up as a momentary streak of light in the night sky – that’s a meteor, also called a shooting star or falling star. Most meteor showers are best seen after midnight, but the light from the waning gibbous moon will mar the view, so go outside late in the evening and watch it until the moon rises. Get away from bright streetlights, dress warmly, protect yourself against mosquitoes, lie back in a lounge chair and look up high in the east for best results. This is a long-lasting shower which will continue until mid-August; but the best viewing will probably be the next two nights.
Fri Jul 30, 2021 GALILEO SEES SATURN
Four hundred and eleven years ago today, on July 30th in the year 1610 Galileo set up a small, hand-made telescope on his veranda in Padua, and aimed it at a bright yellow, star-like object in the night sky. And so he became the first person to observe the planet Saturn telescopically. But what did he see? Just a big round blob of light, and on either side, two smaller blobs. Were these two large moons of Saturn? Did the planet have handles? Or ears? He couldn’t tell. His crude telescope only magnified objects about 30 times, which wasn’t enough to resolve the mysterious somethings that flanked the sixth planet. Galileo recorded what he saw, then moved on to other discoveries. It wasn’t until 1655 that better telescopes resolved those blobs into rings. Now, 400 years later, even small telescopes are good enough to resolve the rings of Saturn; late tonight you’ll find the ringed planet low in the southeastern sky, to the west of the planet Jupiter.