Venus is not easy to find but with a good horizon and determination you will succeed. The map shows the planet as seen from mid-northern latitudes about 15 minutes after sunset this evening. Mercury will require binoculars. Created with Stellarium
If you’ve been pining for Venus, the goddess of beauty, your days of anguish will soon be ending. Venus has returned to the evening sky after a long daytime engagement with the sun. Put plainly, it’s been too near the sun to observe, but beginning now and continuing for the remainder of the year, the brightest planet will part ways with the keeper of the light and inch its way into the night.
Venus won’t easy … at first. Tonight it will be visible for a brief time starting about 15 minutes after sunset. Look very low in the southwestern sky some 3 degrees above the horizon a little more than one outstretched fist to the left of the sun. Binoculars will help you spot this single bright “star”. If your skies are very transparent, you might even get to see Mercury just 2 degrees below Venus and very close to setting. Over the next few evenings, Venus and Mercury will remain near one another and remain a challenging duo. Of course, if you live in the southern U.S., the two planets are tipped are at a steeper angle to the horizon and noticeably easier to see.Come November, Venus will set later and gradually become easier to see.
The lunar crescent -- just 2 1/2 days before new -- cuts a sharp figure in the sky before sunrise this morning. Photo: Bob King
My daughter came up to visit from college over the weekend. She always marvels at how dark it is where we live and how many stars she can see compared to the Big City. When I helped her scrape frost from her car windows early this morning, the waning crescent moon sent us a small smile. There are only two days left to see the moon at dawn before it new moon on the 26th and its return as a crescent in the evening sky.
Dewdrops not only focus the sun into tiny bright images, they also magnify the veins of the leaf. Photo: Bob King
The other morning while dashing off to work, I was stopped by the sight of a dew-dabbed leaf in my front yard. Looking closely, you can see how the curved surfaces of the drops act like the curved lenses in a pair of glasses, binoculars or telescope to focus the sun’s image into tiny brilliant spots on the leaf’s surface. The convex drops also serve as ephemeral magnifying glasses, too. Take a look at the enlarged view of the leaf vein under the second drop to the left of the big one at top.
I wonder if raindrops or dewdrops were our ancestor’s first inspiration for using rounded, clear objects to magnify, focus and clarify both distant and nearby scenes. While raindrops aren’t very handy when you need a lens, the same principle of curved surfaces can be applied to glass-making, an art discovered around 5000 B.C. The earliest known lens to currently be unearthed was made in the year 750 B.C. and found at the Assyrian palace of Nimrud in modern-day Iraq. It’s believed to have been used as a magnifying glass or as a burning-glass to start fires.
The infamous Nero, who become Roman Emporer in 54 A.D., watched gladiator fights through a monocle apparently made of emerald crystal. It’s unclear if it was ground out to correct nearsightedness or if he simply was following a popular belief at the time that vision is improved and refreshed when seen through the green gem.
Reading stone from the Middle Ages
During the same era, glass globes filled with water were used to magnify written documents to make them more legible to those like me whose near-vision declines with age. Later, hemisphere-shaped glass lenses called reading stones were used to magnify text for easier reading. Around 1284, the Italian Salvino D’Armate is credited with inventing the first wearable pair of eyeglasses. More than 300 years would pass before Dutch spectacle makers in the late 16th century would place two different lenses one behind the other to create the first telescope.
In researching this information, I came across a fascinating early reference to a telescope from the works of Roger Bacon, the English philosopher and Franciscan friar who was one to advocate the modern scientific method as a tool to understand the world.
This from his Opus Majus: “For we can so shape transparent bodies, and arrange them in such a way with respect to our sight and objects of vision, that the rays will be reflected and bent in any direction we desire, and under any angle we wish, we may see the object near or at a distance … So we might also cause the Sun, Moon and stars in appearance to descend here below.”
And that was in the year 1268!