Eclipse of May 20, 2012

Solar eclipses don’t happen every day, let alone every year, but worse than that they almost never—well, maybe once in a lifetime—occur where you happen to live.  That means no matter the day, no matter the place, the eclipse chaser must somehow come to the eclipse, because the eclipse has surely not planned to come to her.

The Eclipse of May 20, 2012 was within driving distance for San Diegans, passing over central western Utah and during a time of year when clear weather would be likely.  We used NASA tables to determine the path of the moon’s center and then checked out all highways this path would cross.  The I-15 was the most popular choice for eclipse chasers, but arriving at one of the designated events, we felt that observing the eclipse with a large crowd gathered along the I-15 could have its downsides.  Being freshman eclipse chasers was turning into some hard work!  Well, a frustrating driving experience, anyway, up and down the interstate and up and down the interstate, as we looked for suitable haven.  In other words, if we wanted to capture photos of the eclipse from a perfect spot that enabled a nicely centered (annular) solar ring, we would need a lot of effort, and even some extra time, to find it along the already-packed interstate.  The answer was to drive a respectable distance to the west into Utah farmland.

The NASA track also intersected Highway 56 just northwest of Iron Town Road.  We actually ended up with some extra time. A quick detour to the remains of Old Iron Town, which is a historical site with magnificent kilns once used to process the nearby ore mines, also gave us our first-ever opportunity to see a hard-to-find cholla cactus called Claret Cup (Echinocereus coccineus)!  

Any eclipse event transpires quickly, but this event was expected to exhibit especially brief lunar/solar alignment at our geographic location.  We would have only a few seconds. To prepare, we needed to be set up, prefocused and also well-practiced at finding the target with the alt-azimuth mounts (without actually looking into the sun), whether the setup be camera-on-tripod or theodolite-on-tripod.  Granted, eclipses are most commonly photographed through DSLR cameras using proper filters, but projection-onto-card worked very well through to barrel of the the Nikon-made telescope of a surveying theodolite (actually, a total station). This is actually not recommended because of the sensitive components of the laser hardware in the station.  On the other hand, plain optical tubes, including those of transits or other refracting telescopes work just as well or better.

In an annular eclipse, the moon is too far away from the earth to completely cover the sun, producing the ring.  The sunlight forming the ring remains far, far too bright to look at it with the naked eye.  Even by the time of maximum eclipse, daylight had faded only very slightly, but surprisingly the air had become noticeably cooler and became for awhile a breeze from the direction of the eclipse.  Sunset began in subdued orange glow as the eclipse began to end, the light available at that time being comparable to a sunset on the planet Mars.

Click on the little ⇒  arrow button lower right of any photo below to enter slide show of enhanced views of the photos.

The bright image of the sun peeks through the eyepiece of a theodolite. Observing the sun directly through the eyepiece, even for a second, would cause blindness.

An assembly of folded card stock is used to maintain constant distance and focus from the eyepiece of the theodolite.

The sun's image is projected through the eyepiece onto card stock. The two vertical lines are formed by the sun's rays passing through the telescope's brackets.

Moving very quickly across the earth's surface, the centered ring is seen for fleeting seconds, making a photograph of the illuminated card quite difficult. Fortunately, the image is projected perfectly through the theodolite telescope onto the card behind it.

Diffracted through the needles of a Juniper tree, the multiple images of the partially eclipsed sun take on an eerie, shadowy glow. The little eclipse images are upside down. It's the same principle as the original pinhole camera.

This massive kiln is located at the Old Iron Town site on Iron Town Road west of Highway 56, a hop, skip and jump on our way to our appointment with the eclipse.

Growing at nearly 6,000 feet, seeing this colorful type of cholla cactus, Claret Cup, in Old iron Town was rare for us, and like the eclipse, a great coincidence.