Any time something passes in front of the sun, you get a shadow. I've watched plane-shaped shadows scoot across valley floors in Central Nevada. I've also seen shadows of hot air balloon shadows and ducks in formation moving across the land. Sometimes, however, you see something even cooler. Here's an image of the Venus transit from June 5, 2012 taken from my phone from the roof of Northrop Hall at the University of New Mexico in Albuquerque. I took this picture through a telescope with a solar filter attached to its end. It's a neat shot of a very small part of the sun being blocked out by our sister planet, Venus.
This isn't the first time that I've seen part of the sun blocked out. Also in 2012, I was in northern New Mexico overlaying two pairs of sunglasses to observe an annular eclipse, when the moon is too far away (and too small) to block out all the sun. Because there is a ring of brightness around the moon, it is still quite bright. So bright that I learned that nesting sunglasses does not dim the sun well, which left me with a headache and a horrible purple afterimage in my eyes.
Humans have had an interest in things that block out the sun for centuries. The ancient Chinese predicted eclipses. Mayan scribes also recorded eclipses with an eclipse symbol (chi' ibal kin, "to eat the sun") and their mathematicians predicted them as well. My interest, however, in things that block the sun (physical sunscreens) isn't religious or because I am creating an accurate calendar. To me, these events are simply rare and cool.
Eclipses have their uses, however. Total eclipses have long been known to block out the brightest part of the sun and allow observers to see the sun's outer atmosphere, its corona, streaming away. SOHO, a NASA/ESA solar observatory, has a physical blinder blocking out the bright sun so that its cameras can observe space weather created by solar flares and coronal mass ejections that affect Earth.
And sometimes, like in the picture above, shadows on the sun are simply pretty.
