Jupiter, Venus, Galileo, my old man and me

The morn­ing sky right now reminds me of my mis­spent youth. My father, who never grad­u­ated the ninth grade, was inex­plic­a­bly an opera buff. How could I for­get the trips to Cleve­land to see the tour­ing com­pany of New York’s Met­ro­pol­i­tan Opera? I am an opera afi­cionado myself to this very day.

But my old man’s opera obses­sion had a hid­den ben­e­fit. He owned a cheap, three-buck pair of opera glasses. They had plas­tic lenses and made the per­form­ers on stage look like cir­cus clowns. Come to think of it, some of the char­ac­ters rep­re­sented were indeed cir­cus clowns, but never mind.

Those opera glasses were my first and only opti­cal aid, and they turned me on to the won­der and majesty of the cos­mos. In the morn­ing before school espe­cially, I often rev­eled in the beauty of the sky.

Right now, the two bright­est plan­ets grace our mid-autumn sky dur­ing deep morn­ing twi­light. Yel­low Jupiter dom­i­nates the south­west. Below it is the bright star Alde­baran in the con­stel­la­tion Tau­rus, the Bull.

Even more bril­liant Venus blazes, purest white, near the east­ern horizon.

In between and above the two plan­ets are a plethora of bright stars. Above Jupiter is Capella, the She Goat, in Auriga. To the left of Capella are the famous twins Cas­tor and Pol­lux in Gem­ini. Between Jupiter and Venus is the star Pro­cyon in Canis Major. Between and below Jupiter and Venus is the bright­est star of all — Sir­ius, the “Scorch­ing One” in Canis Major. Below Jupiter is the plethora of bright stars in Orion, the Hunter.

The view is a life changer if you can man­age to catch it at just the right time and place: just as morn­ing twi­light begins at a place where trees and build­ings don’t block the view from the east to the southwest.

Believe me, it’s worth the trou­ble. The pres­ence of Venus and Jupiter reminds me how Galileo changed the world when he first looked at them in his crude tele­scope 400 years ago. They cer­tainly changed my world when I was 10 years old. Armed only with my old man’s opera glasses, I sal­lied forth to repli­cate the dis­cov­er­ies of the mighty Galileo.

Like the famed astronomer so long before, I trained my prim­i­tive instru­ment on Jupiter and saw its four bright­est moons lined up around it. They orbit so quickly that I could watch them move by prop­ping my elbows on the back of a kitchen chair to steady my binoculars.

When the astronomer dis­cov­ered his “Galilean moons,” as we now call them, he rec­og­nized their impor­tance to the rad­i­cal the­ory of Coper­ni­cus, who sug­gested that the sun, not Earth, was at the cen­ter of things. Oppo­nents of Coper­ni­cus argued that an orbit­ing Earth would leave its moon behind as it moved. Yet Jupiter had plenty of moons trav­el­ing with it. Could Coper­ni­cus be right?

Two months later, I saw Venus as a thin cres­cent just as Galileo had. Venus has phases like our moon! Galileo soon real­ized that the phases pro­vided even more valu­able evi­dence for the Coper­ni­can solar system.

Right now, Venus looks gib­bous, fat­ter than a half Venus. As the planet moves closer to the sun over the next few weeks, it will become nearly a full Venus before it gets to close to the sun to see.

Venus gets around the sun faster than Earth because Venus is the sec­ond planet from the sun and Earth is the third. When Venus is on the far side of the sun, the whole disk of Venus is illu­mi­nated from our Earthly van­tage. As Venus moves away from Earth and hence swings around to our side of the sun, an increas­ingly large part of its front side is illu­mi­nated. From Earth, Venus appears to grow toward “full” Venus.

The con­clu­sion was easy and obvi­ous to Galileo and to me. Venus must be on the other side of the sun from us. As it approaches the sun from our van­tage, Earth, the sun and Venus become increas­ingly lined up with the sun in the middle.

While you’re look­ing, imag­ine the plan­e­tary motions that cause Venus to grow, and you will quite lit­er­ally feel the Earth move as Venus and Earth orbit the sun.

So what did those opera glasses do for me? They taught me how to think, but they also taught me how to feel. Thanks, Dad.

You can sit there and read about Galileo’s sem­i­nal astro­nom­i­cal obser­va­tions, or you can go out­side and look for your­self. The expe­ri­ence just might release your inner Galileo or, if your heart is truly pure, the lost 10-year-old who lies dor­mant deep within us all.

Tom Burns is the direc­tor of Perkins Obser­va­tory. He can be reached at tlburns@owu.edu.

Posted by Tom Burns on Oct 21 2012. You can follow any responses to this entry through the RSS Feed. Comments can be made below.