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A tale of two craters

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A tale of two craters

I was out with my 4 inch refractor in my back garden in Dublin, Ireland, on the evening of Tuesday the 24th of March, 2015. It was a lovely clear night with Jupiter also on show during breaks from moongazing. I always use a diagonal in my refractor, often bent at some odd angle as I like to sit when I observe. So the orientation of the Moon can often be a little strange. I have a few 'signposts' I use in order to get my bearings, such as Archimedes, Plato and Mare Crisium.

I had a pretty detailed map on Tuesday that I got at the Sky and Telescope Store and, instead of just using it for orientation, decided to explore the area in a bit of detail. Most craters on the Moon are named after famous individuals associated with our satellite, and those on Mare Crisium, the 'Sea of Crises' are no exception. After a little map reading, I decided to make the focus of my evening’s viewing a pair of craters named after the founders of two of the most famous Observatories on Earth.


Figure 1. The Lick Observatory today

Our first Observatory is that built with the fortune amassed by James Lick. Lick arrived in California in 1848 after spending almost three decades in South America. He immediately bought up as much land as he could in a growing shanty town known as San Francisco, using Peruvian gold brought home from his South American adventures. His timing could not have been better, a mere seventeen days after his arrival, gold was discovered at Sutters Mill, kicking off the 'California Gold Rush'. Like Yerkes (more of him later!) he was anxious to leave a monument to posterity and he was persuaded that a dome housing a 36 inch Clark refractor, the largest in the world at the time, was the way to do it.


Figure 2. Lick crater from Lunar Orbiter 4, image courtesy of NASA.

Through my TV101, Lick is a flooded 'ghost crater' with a smaller crater to the North, Greaves, almost touching it. Greaves was deep in shadow on the night I looked at it. The centre of Lick is a little whiter than the rest of the crater, indicating to me that it might be convex. On examining photographs of the feature, it became apparent that there has been quite a bit of vulcanism on the floor of the crater, there are many rilles here which could scatter light, explaining this effect.

First light for the Lick refractor occurred in 1888 and it was the largest refractor on Earth until the Yerkes Observatory 40 inch, also a Clark, was constructed.


Figure 3. The Yerkes Observatory

 The Yerkes Observatory is named after Charles T. Yerkes, a businessman who made his fortune financing Chicago's electric railway system. When I visited Chicago a couple of years ago, I made sure I took a ride on 'the 'Loop', an elevated line through the birthplace of the skyscraper, and spared a thought for Mr Yerkes, who made my ride possible. In addition, I did a walking tour with the Chicago Architectural Foundation who taught me a little of Yerkes roller-coaster life, replete with blackmail, larceny and prison terms. Everyone loves a rogue, however, Yerkes, concerned with his public image after multiple scandals, was persuaded by George Ellery Hale to crack open his bulging wallet to pay for an Observatory in order  to restore his image. "I don't care what the cost, send me the bill!", he announced to the local journalists when he decided to proceed. The papers claimed he would spend a million dollars to "lick the Lick". The Observatory is an architectural masterpiece, clearly, no expense was spared. The architect, Henry Ives Cobb, was fond of ornamentation rooted in classic mythology. At Yerkes, he let his imagination rip, with statues of animals, signs of the Zodiac, phases of the Moon, and many other fantastical details.

File:Dorsum Oppel - LROC - WAC.JPG

Figure 4. Yerkes crater, image courtesy of NASA.

I have always thought an Observatory was an odd choice for charitable works to redeem a man's character. However, at the time, observatory building was in vogue and Hale was a persuasive individual, with an impressive track record of founding Observatories, including Mount Wilson and Palomar.

Through the telescope, the crater commemorating Yerkes is also a lava flooded 'ghost crater', near the Western edge of Mare Crisium. The rim of the crater is almost completely submerged to the East.


Figure 5. The magnificent entrance to Yerkes Observatory

So, within the same lunar sea lie two craters celebrating the lives of the men who bankrolled two of the largest refractors on Earth. Given the colourful backgrounds of both men, perhaps it is particularly apt that both reside in the 'Sea of Crises'. It is a little sad that this era of privately funded Science on a grand scale is over. Given the onerous oversight requirements attached to research funding nowadays, it is unlikely that any future Observatories will boast a comparably exciting Genesis. So if you are ever in California or Wisconsin, do visit, and be sure to remember their founders fondly, that is all they ask!!

  • A6Q6, Perseus_m45, MarkGregory and 5 others like this


Very enjoyable article.  I'm always pleased to learn the background info about the objects I observe.



Apr 16 2015 11:13 AM

Well done. I find it curious that both these men found their names attached to lava flooded ghost craters.

    • DocFinance likes this
Apr 16 2015 02:33 PM

Thanks for the informative article, I really enjoy Lunar Observing. I think it is often an overlooked object especially for Deep Sky Observers. 

Nice piece.  Thanks.

Having been a Wisconsinite until the age of 40, and not having ever taken the chance to visit the Yerkes, I loved stumbling into Skyaddict's well-written article. On my next visit back to my home state (I've been living in Ohio and Mass these last 27 years), I'll be sure to make time for a visit. Thanks for great read, and the incentive to add this to my bucket list.

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