November 2011 - Utah-Astronomy - mailman.xmission.com

MSL in Utah skies
by Patrick Wiggins 26 Nov '11

26 Nov '11

A reminder that with a successful, on time launch earlier today of the NASA's MSL we here in Utah will have a chance to get some images of the departing craft tomorrow morning. No idea how faint it will be but I'm guessing it'll be so faint no one is going to see it. However, we may have a chance to get some images. Calculate your local circumstances here: http://ssd.jpl.nasa.gov/horizons.cgi patrick Go MSL!

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see you at the Pit
by Mark Shelton 26 Nov '11

26 Nov '11

See you all that are coming out to the Pit, My wife thinks I am NUTS. Maybe she is right. Mark

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OT: Happy Thanksgiving
by Chuck Hards 26 Nov '11

26 Nov '11

I hope all of my friends and astronomy acquaintances have a happy, enjoyable Thanksgiving Day holiday. Though I've had a lot of personal setbacks in the last few years, I still have many more things to be thankful for. Life is good, on the whole. Now, back to astronomy. Sorry to waste the time of those who only want to post about the world's second-oldest profession. ;o)

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Another milestone for amateur astronomers
by Josh 26 Nov '11

26 Nov '11

Thought the list would be interested in this. A New Zeland amateur astronomer named Rolf Olsen imaged the planet forming disk of a near by star with a 10" telescope. http://blogs.discovermagazine.com/badastronomy/2011/11/26/amateur-astronome…

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Pit and Pole
by Mark Shelton 26 Nov '11

26 Nov '11

Hi, Is there any interest in going to the Pit tonight? I will bring my HEATER. Weather looks ok. Please let me know if you are interested Mark Shelton

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For the Brave at Heart
by Jay Eads 26 Nov '11

26 Nov '11

I just work up from a nap and I know Mat is heading out tonight and I was going to but I'm not feeling so well tonight. Saturday night is forecasted to be clear and cold so I am going out to Pit n Pole if that forecast holds for observing from 6:00a.m. until 12:00a.m. or so. If your interested in going, dress warm in layers and let me know if you want to go out and try some late fall observing (no, not winter observing yet). -- Jay Eads

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Sun update
by Canopus56 25 Nov '11

25 Nov '11

There is a nice string of sun spots across the solar disk. Tomorrow may be clear. See photo at http://spaceweather.com/ - Kurt

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Re: [Utah-astronomy] IMPORTANT: Alton Coal Mine
by Canopus56 25 Nov '11

25 Nov '11

I was able to download the Appendix on Dark Skies Impacts prepared by Dark Sky Partners, LLC and SWCA Environmental Consultants. The file is 13 megabytes in size, and it would take sometime to download it if you do not have a high speed internet connection. If anyone is still unable to download the report, if you like, I can post a local copy on my Salt Lake website. That may be easier for you to grab. The report is prepared by Dark Sky Partners, LLC and SWCA Environmental Consultants: Dark Sky Partners, LLC http://darkskypartners.com/DSP_about.htm ``Donald R. Davis, Ph.D. is a planetary astronomer, working primarily in the field of small body evolution and dynamics. He has been actively involved in light pollution educational and control efforts since 1986, serving as president of the International Dark-Sky Association (IDA) Board of Directors (1997-2005), and sitting on the Pima County Outdoor Lighting Committee (1986-2005; chair 1994-1998). He has been involved with the quantitative measurement of skyglow since the pioneering study done at Organ Pipe National Monument (1995).'' DSP Website ``About'' page, accessed 11-23-2011. SWCA Environmental Consultants http://swca.com/ The key conclusion of the report is: ``This study presents results from computer calculations of the sky brightness due to mining operations in the Alton Coal Tract when viewed from Yovimpa Point in Bryce Canyon National Park and from Brianhead Peak near Cedar Breaks National Monument. Two scenarios were suggested by Alton Coal Development for analysis, one for typical lighting and one for brightest expected lighting. The calculations show that, under the typical lighting scenario, the lighting would not produce a sky glow visible above the horizon from Yovimpa Point; any sky glow would be seen only when looking just above the mine site and just below the distant horizon. The predicted sky glow would be less than that produced by several small towns in the general area that are usually not discernable according to the National Park Service, and significantly less than the visible glow arising from the distant large cities of St.George and Cedar City, Utah. Under the brightest lighting scenario described in this report, the sky glow seen from Yovimpa Point is found to be comparable to that produced by small, local towns but still less than that of the larger distant towns.'' Report at page 3 (April 2009). The report also incorporates at report Attachment 2, an April BLM memo concluding, based on the Dark Skys Report, that ``As presented, lightscape impacts to national parks will be negligible to minor.'' Another key emphasis of the Dark Skies report is direct visibility analysis through GIS terrain mapping. The report concludes that ridgelines will obscure direct visibility of the portable lights. The ridgeline obscuring conclusion only relates to two specific, but ``representative'' observing points at Yovimpa Point and Brianhead Peak, as discussed below. Proposed mine lighting will by portable floodlight units from Baldor shown on their website: http://www.cascade-machinery.com/38246/442279/Towable-Generators/Power-Lite… The Baldor website catalogue only a model with four metal halide lights, and the report includes a Baldor product sheet that appears to be the same model. The report recommends mitigation by special shielding on the flood lights. The shields are manufactured by MUSCO Lighting. http://www.musco.com/ See a product example at: http://www.musco.com/outdoor/sportscluster.html The report expresses its conclusions regarding skyglow in nanoLamberts, and thus effects are not stated in units familar to amateur astronomers. A good starting point might be to ask the BLM to have a revised report issued stating skyglow effects in NELM magnitudes, Magnitudes Per Square Arcsecs (MPSAS) and in nanoLamberts. I have a nanoLambert to magnitude conversion table and will try to post that up on my local website next week. Having experience with similar unshielded industrial floodlighting at the Morton Salt Flat facility on I-80 at the north end of Skull Valley and at the NL Industries plant on the north side of the Salt Lake, I have a hard time accepting the Dark Sky Partners' conclusion. The Morton Salt flood lights essentially ruin Skull Valley as an observing site for 20 miles down the valley, and skyglow from the lights, from an amateur astronomy viewpoint, affects limiting magnitudes up to 60 or 70 degrees above the local horizon. There is easily seen skyglow from the NL Industries plant on the east side of the Grass Valley (at the Lakeside dark sky site) even though the plant is more than 20 miles away. Similarly, the heavily lighted Envirocare facility obscured by the west ridge of Grass Valley, visibly light pollutes the west horizon of Grass Valley. The Envirocare facility is over ten miles from the center of Grass Valley. I have not read the report in depth. With respect to skyglow, Dark Sky Partners is using Garstang's algorithm, which is the generally accepted method. Although I am not physics or mathematics trained, I have previously read the Garstang articles cited by the report. But I'll keep an open mind on this, and I will try to read the report in more depth next week. Giving the report a quick read, a few immediate and preliminary questions arose. First, the report's analysis does not appear to be based on any actual physical assessment of the current night sky visibility from points in the park or actual measurements of light pollution on the horizon. The report only estimates existing light pollution from nearby towns using computer models to extrapolate values from similarly sized communities. See Table 3 in the report. The report is based on computer model estimates of what existing dark sky values are at the zenith and horizon at the park. The analysis is not based on any real skyglow data. Some hint as to why computer estimates instead of the collection of real skyglow data was used is given in an NPS memo attached to the report by NPS Ranger Chad Moore. I interpret the following quote from the memo as indicating there was some administrative goal to complete the light pollution environmental analysis by the spring of 2009, thus preventing the collection of data by setting up photometric monitoring stations during the summer of 2009: ``The difficulty with using a site within Cedar Breaks is that no all-sky brightness data exists there. With winter approaching, it is unlikely that suitable data could be acquired there before June 2009. While models produced from an observation point within the park (as opposed to at Brianhead Peak) would be slightly more accurate, the portion of the impact to the current condition would be less accurate since no data exists.'' NPS Memo dated 9/26/2008 at memo page 1, Appendix B to the Dark Sky Partner Report . These events raise the question in my mind as to why actual skyglow data was not collected during the summers of 2009, 2010 or 2011, considering that the DEIS is being released in the fall of 2011, and considering that the Park is a nationally unique dark sky resource. Second, the report's was not based on actual measurements of the photometric characteristics of the proposed lightning. It is based on the consultants' best estimate of what light pollution the Baldor units will produce, as noted on page 9 of the report. ``The portable lights would utilize 1000 watt metal halide lamps producing 110,000 lumens each. These fixtures are mounted with adjustable gimbals, allowing the fixtures to be aimed in different directions and at different angles relative to the horizon (see Appendix A). Although DSP contacted Baldor Electric Company, manufacturer of a potential portable lighting system suggested by ACD representatives, the representatives of Baldor were unable to produce the photometric information needed to accurately evaluate the fraction of light directed upward as a function of aiming angle of the fixtures. Therefore, for this study DSP is forced to estimate this fractional uplight value.'' Report at 9. Similarly, the project's proponent did not provide specific information on the models of mining trucks to be used, and so the consultant had to make an informed guess at the number of trucks and their headlight brightness to be used at the site. The report at Table 3 summarizes what light pollution outputs that the mining trucks will produce, but does not appear to state the total number of vehicles that they assumed would be used: ``For the vehicular lighting we have no specific information either on the manufacturers and types of the mining vehicles to be used, nor for the lighting that would be installed on this equipment.'' Report at 10; see Table 3 at 12. As with the existing light pollution situation, analysis of the vehicle light pollution is not based on actual engineering or environmental data, it is based on the consultants' best informed guesstimate. Third, the report is based on the NPS request that only representative observing points at Yovimpa Point (+37 28 20 –112 14 25) and Brianhead Peak (+37 40 52 –112 49 50) be considered. As the report notes: ``The observation sites listed in Table 4 were set in consultation with NPS and BLM representatives. These sites were chosen to provide a representative evaluation of the sky glow impacts of lighting in the ACT for visitors to BCNP and CBNM.'' Report at 10. The report includes an attached memo by the NPS's Chad Moore discussing that matter. The implication of this is that local amateur astronomers may have knowledge of other commonly used observing points with significant night sky esthetic values, and the impact on those observing points is not considered by the report directly. Rather, impacts on other areas are assumed based on the two ``representative observing points.'' Fourth, the report's skyglow model does not include as a parameter increased aerosol dust that would be kicked up by mining operations. That report states that this omission was based on NPS instructions, and the consultant qualifies their conclusions on the grounds that mining operations could be expect to inject aerosols into the atmosphere: ``These atmospheric parameters describe very clear conditions and will lead to modeling results that will show smaller impacts from potential lighting in the ACT as well as from nearby towns than will typically be the case. The NPS night sky team purpose in recommending these clear conditions for the analysis is to show what the impacts would be during the "best" observation nights, when the air is clearest and the stars most visible. It is important to recognize that 90% of the time the air will be less clear, and the impacts larger.'' Report at 9. The report also states with respect to dust mitigation that: ``Methods to mitigate dust reduction such as paving heavily used roads, wetting the ground or limiting operation during windy conditions can considerably decrease aerosol/dust concentrations in the lower atmosphere and therefore light scattered toward the observation points from the mine site. The sky glow reductions from this mitigation are unknown.'' Report at page 24. Those aerosols (dust) could be reasonably expected to increase skyglow by reflecting light from the portable mine lights. In other words, the dark sky analysis is not based on the actual environmental effects of the proposed coal mine, in terms of increased dust being injected into the air above the mine. The report's analysis is based on the assumption that there are no impacts or that all dust can be mitigated with technology, e.g. - paving roads in the mine and dust suppression by watering. Fifth, the consultant makes no legal analysis of whether the proposed mitigation - floodlight shielding - would be allowable under worker health and safety regulations of OSHA or by federal and/or state regulators of open pit mining. For worker safety, regulators may require many more floodlights during night operation than is assumed by the consultant. Sixth, and to end on a positive note, the consultant notes that the night light pollution can be easily and fully mitigated by a ``no action'' alternative: ``Performing mining operations during daylight hours only would allow the elimination of 86%-92% of the total lighting, and completely eliminate all unshielded lighting.'' Report at page 23. As with teen pregnancy, abstinence is 100% effective, but only if the prescription is rigorously followed. I hope the above notes help, is free from any misinterpretations of the documents, and that my notes do not generate more heat and light than understanding. (Pun intended.) If anyone sees any obvious misinterpretations, please let me know. Finally, given the widely varying political views of club members, which as a matter of consensus we try to collectively avoid picking at on this listserv, I would appreciate a read on whether the group as a whole, or any individual members, are uncomfortable with this discussion. My personal feeling is that dark sky advocacy is an appropriate topic for this listserv. The above quick review is not intended as legal advice. These notes are my impressions made in my capacity as an amateur astronomer and an occasional night-sky recreation user of Utah's southwest federal public lands, which nationally are a unique dark sky resource. People should read the Dark Sky Partners' report and reach their own conclusions. Clear Skies - Kurt

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Need Ride to SLAS Transitional Board Meeting
by D P Pierce 25 Nov '11

25 Nov '11

I would like to get a ride to the SLAS transitional board meeting Tuesday night. Just me and my 36 lb fold up wheelchair which fits in most trunks, many back seats and hatchbacks and all pickup truck beds. *I could ride TRAX to the 450 S & Main St station but being in that part of town after dark makes me nervous.* ** *Deloy Pierce, Large Bored Member*

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NGC 1990
by Jay Eads 25 Nov '11

25 Nov '11

Been searching around the net since I'm doing the H400 II now and in my next list of observing includes NGC 1990 and the nebula around it. I've read this is really just one of those targets like Messier 40 that is fictional. Anyone here confirm what I've found online about this topic? I'll still look but won't take too much time on it. -- Jay Eads

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