01 January 2017
ACQUISITION OF NEW DARK SKY SITE
If you've read through the Equipment page on this website, you know that my future plans have been to acquire a new, larger telescope for my imaging activities. Some of my previous acquisitions (mount, focuser) have been made with their compatibility with a new telescope in mind. However, I also made the decision that getting a new, bigger telescope was not enough. While the skies at the current SOCO site are not too bad, they are far from pristine, light pollution-free conditions. Only pristine dark-sky conditions would bring out the full potential of a new, bigger imaging scope. For this reason, I have been engaged over the past year in finding a pristine dark-sky site for the future location for my astro-imaging activities.
My search has taken me to a number of locations in the U.S. Southwest. I've looked at sites in Val Verde County and Edwards County, Texas; the area around Big Bend National Park; sites around Alpine, Texas; and even sites in southern New Mexico. All of these potential sites had good sky conditions, but they also had positive and negative aspects related to living in that area. One obvious one is that, if you're going to have pristine dark skies, you're going to be living in the middle of nowhere! So, unless you really want to be a hermit, everyday life at these sites is going to very solitary. As a result, I eventually rejected all of these potential sites.
In the fall of 2016, a new publication appeared called The World Atlas of Light Pollution. This booklet by researcher Fabio Falchi presented the general results of mapping world-wide levels of light pollution, derived from several years of nighttime satellite observations and atmospheric modeling. The publication presents maps of the continents (displayed as color images) indicating levels of clear-sky light pollution according to a color-coded scale ranging from black to white. The lowest level in these maps (shown by black) indicates "no significant light pollution". Looking at the map for North America, one could see the familiar pristine dark-sky conditions of the Big Bend area in Texas and rural New Mexico— places that I had previously investigated in my search for a dark-sky site. However, something new caught my eye in this map— a small region of pristine sky conditions to the east of the current SOCO site. Overlaying a copy of this map with a regional Google map, I quickly ascertained that this small area of pristine sky conditions was contained within King County, about 100 miles east of Lubbock, Texas.
I had known that this general area in the state had good skies. A previous study in which levels of light pollution were modeled from population density (see the light pollution maps for sites on the Clear Sky Chart Homepage) had suggested that skies in this region were quite dark, although not pristine. According to the Bortle Scale, this area had a value of 2, which indicated a "truly dark site". But not a value of 1, indicating the darkest sky conditions. Still, one astronomical site (Comanche Springs Astronomy Campus) is located in this general region and boasts of its dark skies.
The results in The World Atlas of Light Pollution were drawn from a more detailed scientific article, "The new world atlas of artificial night sky brightness" (Fabio Falchi, Pierantonio Cinzano, Dan Durisco, Christopher C. M. Kyba, Christopher D. Elvidge, Kimberly Baugh, Boris A. Portnov, Nataliya A. Rybnikova, and Riccardo Furgoni, Science Advances, 10 June 2016). In this article, sky darkness is divided into 14 levels, more than in the The World Atlas of Light Pollution. In this scale, the darkest level represents pristine dark skies that are only limited by airglow (analogous to Bortle Scale 1). From the information presented in this article, I was able to draw a rough map of sky conditions in the King County area (Figure 1). In this figure, the dark gray portion represents pristine sky conditions, while the light gray portion represents near-pristine sky conditions (boundaries are approximate). The location of the Comanche Springs Astronomy Campus is indicated.
Figure 1. Dark sky conditions in the area around King County, Texas.
The identification of this pristine sky region was a very exciting development. It's only about a 90-minute drive from the existing SOCO site. To verify the sky conditions, I drove out to this area on several clear moonless nights in the late summer of last year. Viewing conditions there were, in a word, phenominal! I had not seen such dark skies since I had driven through the Arizona desert during the 1970's. The Milky Way in Cygnus was very bright and was laced with streamers of dark nebula. The Northern Coal Sack was clearly visible. The Andromeda Galaxy (M 31) was bright and star-like, while the Triangulum Galaxy (M 33) was a faintly visible patch. The stars were so bright and numerous that it was difficult to make out the constellations. Stars extended down to the horizon— Orion rising was spectacular. There were no significant light domes along the horizon, and only one or two security lights in the distance.
So, what makes this area such a pristine dark-sky site? When you drive through this area in the daytime, the reason is obvious— there is nothing out there! According to Census data, King County is the third least-populated county in the U.S., with a permanent population under 300 people. The county seat (Guthrie) has maybe a dozen homes and not even a gas station. Most of the land in the county is undeveloped rangeland divided up into several huge cattle and horse ranches (most notably the 6666 Ranch and the Pitchfork Ranch). The few farmsteads are widely scattered across the county. And, good for the future of astronomy, the population in this county has been steadily decreasing over the past few decades.
The discovery of this dark-sky region completely changed my search for a new astronomy site. The proximity of this region to where I currently live meant that I would not actually have to live at the new site— I could just commute there to image. So, I set about trying to find some property in the dark-sky region. Unfortunately, this is where the lack of population works against you— if there are not many people living there, then there are not many properties coming up for sale! I spent several months patiently watching the real estate websites for something in this area, but with no success. Then a few weeks back, I was talking to a banker from this area about my interest in establishing an astronomy site there, and he mentioned that he knew someone that had just put their small horse ranch up for sale— it wasn't listed on any website but was just handled by a local realtor. And as luck would have it, it was located within the area of pristine skies!
To make a long story short, I bought the ranch. It has a total of 21 acres and is perfectly suited for developing into an astronomy campus with multiple observatories. It even has a nice mobile home on it so astronomers can spend the night in comfort. A panoramic view of part of the site is shown in Figure 2. It's not much to look at now, but with the participation of two other atronomers from the Lubbock area, it will be developed into a full-fledged astronomy campus similar to the Comanche Springs Astronomy Campus. Initially, we are planning three observatories: a roll-out structure containing a 30-inch (yes, 30-inch!) Dobsonian reflector (primarily for observing); the original SOCO 8-ft domed observatory, possibly containing a 10-inch reflector; and a new 11-ft domed observatory, probably containing a 20-inch Planewave CDK reflector (primarily for imaging).
You'll note in Figure 2 the beautiful clear skies. According to an analysis of NOAA weather data by Michael E. Bakich and Roen Kelly (Astronomy, December 2016, p. 13), this location has on average around 130 to 150 clear days (and, presumably, nights) per year.
Figure 2. Panoramic view of the future astronomy campus.
Sadly, this means that the Sentinel of the Caprock Observatory will soon cease to exist. The new astronomy site is located in the Rolling Plains of Texas, just off the Caprock formation that gave SOCO its name. So, a new name will be found for it. Once operational, this new astronomy campus, with its contingent of formidable telescopes, will become one of the premier amatuer astronomy facilities in the state. I will keep you informed as the development of this site progresses.
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