stevecoe
Reged: 04/24/04
Posts: 2129
Loc: Arizona, USA
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May we PLEASE, get back to the subject we started to discuss?
Steve Coe
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150mm 6" f/8 Celestron Refractor on Sirius Mount
80mmED 3" f/7.5 Orion Refractor
Author "Deep Sky Observing" Springer-Verlag
Author "Nebulae and How to Observe Them" Springer
New Canon Xt astrocamera with Hutech modification
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Bill G.
professor emeritus
Reged: 04/04/04
Posts: 519
Loc: Fort Mill, SC USA
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Don't know! My best guess is at least 7.0. Spent a few years in the missle fields of North Dakota in the 70's. The air would be so dry and clear. Unfortunately, I wasn't into astronomoy at the time. I just know that on many nights we'd be on a site 80-100 miles from the base, not a light visible anywhere, and we would kill the truck lights, wait a few minutes, look up. All we could say was OH MY G*O*D!!! It was one of the most beautiful sights I've ever seen....And that was before I had a clue about what I was even looking at.
..... oh the missed opertunity...
Bill G.
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 I took up astronomy because I don't have time for anything else during the day.......
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stevecoe
Reged: 04/24/04
Posts: 2129
Loc: Arizona, USA
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When we get out to dark skies in Arizona with several folks who have not been out before, some line such as:
"That is the Milky Way?" or "I had no idea that there were so many stars" always seems to happen.
It is lots of fun to see the joy and wonder in other people's voices in the dark.
Clear Skies to us all;
Steve Coe
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150mm 6" f/8 Celestron Refractor on Sirius Mount
80mmED 3" f/7.5 Orion Refractor
Author "Deep Sky Observing" Springer-Verlag
Author "Nebulae and How to Observe Them" Springer
New Canon Xt astrocamera with Hutech modification
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SaberScorpX
Post Laureate
Reged: 01/12/05
Posts: 4121
Loc: illinois, usa
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Gotta admit, the first time seeing the unbelievably thick Milky Way rise over the Red Rocks of Arizona caught me off-guard. For a moment I thought we were about to be clouded-out.
We certainly were- but in a stellar way. 
Stephen Saber
PAC/Astronomical League
http://www.geocities.com/saberscorpx/home.html
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Tom Polakis
professor emeritus
Reged: 12/20/04
Posts: 551
Loc: Tempe, Arizona
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Hi all,
This is one of my favorite subjects, so I feel compelled to reply. I have observed with Steve Coe and others from Five Mile Meadow in northern Arizona. The sky brightness at the zenith is indistinguishable from that at the Texas, Nebraska, or Oregon Star Parties... all excellent sites as well. It is also equally dark as Outback Australia, La Silla in Chile, and remote Namibia, where I have also observed.
The good news is that these "true dark" sites can still be reached (with some effort) in the continental U.S. A good way to find them is on the Clear Sky Clock site, where you can light pollution maps for every state. If the site is in the dark gray, it's very good, and if it's in the black, it's as good as it gets.
Probably more than you care to read, but this essay by Brian Skiff combines experience with measurements.
http://www.astropix.com/HTML/L_STORY/SKYBRITE.HTM
Tom
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warf
professor emeritus
Reged: 10/25/04
Posts: 709
Loc: Wisconsin
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Out on the original Oregon Trail in Wyoming... the advantage of this location is that there isn't 400,000 people in the entire state so light polution of any kind is non-existant out on the old wagon train trails. I have been to the Nebraska and Texas star parties but never seen skies like in Wyoming.
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Marsh
Celestron NS 11 GPS, Denk Standard Binoviewer, Pair of Denk 21 EP, Denk PowerSwitch Diagonal, Denk PST Corrector, Coronado PST Double Stacked, WO ZS80 Anniversary,Celestron 15x70 Binoculars
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SaberScorpX
Post Laureate
Reged: 01/12/05
Posts: 4121
Loc: illinois, usa
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I hear that, Marsh.
At 12,000 ft., the Medicine Bow mountains outside of Laramie
would easily make my Top 10.
And welcome to CN, Tom.
Stephen Saber
PAC/Astronomical League
http://www.geocities.com/saberscorpx/home.html
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starramus
Pooh-Bah
Reged: 09/01/04
Posts: 1124
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I have been to AZ for winter observing trips, but was disappointed. I observed from the KOFA Wild Life Refuge and the Cabeza Prieta Wild Life Refuge as well. I could make out the Phoenix light dome from that far distance. Yuma also is becoming a problem. The problem: too many organisms in too confining of an environment and they like artificial light.
Locally there are a couple of peaks south of where I live. My wife has inlaws who own a large ranch and they have this remote piece of land on one of the foothills. We have an old camping trailer parked up there. There is not one man made light visible. This foothill looks out over wilderness and hope it stays that way. A sky like this is breath taking. Dark yes, but the seeing is usually never really superb. We are on the eastern side of the slopes which does make for a good laminar flow over the ranges. Oh well you can't have everything.
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Tom Polakis
professor emeritus
Reged: 12/20/04
Posts: 551
Loc: Tempe, Arizona
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Quote:
I have been to AZ for winter observing trips, but was disappointed. I observed from the KOFA Wild Life Refuge and the Cabeza Prieta Wild Life Refuge as well. I could make out the Phoenix light dome from that far distance. Yuma also is becoming a problem. The problem: too many organisms in too confining of an environment and they like artificial light.
Yes, the light domes of Phoenix and Yuma are visible at the low desert sites, but they do nothing to affect the sky brightness where you would actually point a telescope, i.e. more than 30 degrees above any horizon other than south.
But... if you want that horizon with *no* light domes whatsoever, you need to be in the pitch black zone on the light pollution maps. Speaking of these maps, I really like the Google Earth image overlay that is now available on the Clear Sky Clock site. Here's an example for the Kofa site.
http://i.pbase.com/o4/64/297864/1/60285728.kofa.jpg
Tom
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Tom Polakis
Tempe, AZ
Visual observing, DSLR photography, lunar & planetary imaging
http://www.pbase.com/polakis/
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Doug Brown
sage
Reged: 02/24/06
Posts: 318
Loc: Fort Worth
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The darkest sky’s I have observed from are at Copper Breaks Texas State Park, mag 7.1 to 7.5. It is just about a 3hr drive from my home and the first time I was there I lost the big dipper because of all the stars I was not use to seeing. I go back 3 or 4 times a year. Yes you can see your shadow by the Milky Way.
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Doug Brown
Though my soul may set in darkness, it will rise in perfect light;
I have loved the stars too truly to be fearfull of the night. ---Sarah Williams, 1868
10” Mead converted to Dob
Broken 20 x 70’s
7 x 50’s
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RRaubach
AstroCowboy
Reged: 01/26/05
Posts: 2173
Loc: Douglas (Converse County),WY
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Last night--in my new observatory built by Backyard Observatories: SQM readings: 21.78 ( as bad as it ever got) to 22.00 ( the best it recorded). I had never before counted 31 "clicks" while it tried to get a reading. southeastern Wyoming mountains ( and, yes, we are near the Oregon trail!)>
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Rodger
Meade SN-10 (UHTC) on Tak EM-200 mount/Antares rotating rings. Moonlite focuser.
Parallax 14.5" Newtonian on HD 200 mount (arriving soon!) w/ conical Royce mirror.
TMB 203 f/7 APO refractor on Tak NJP-160 mount.
Discovery 12.5" PDHQ
Schneider 18x80 "Flakfernrohr" binoculars/tripod mounted. Canon 15x50 IS binoculars
Unihedron Sky Quality Meter
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Starman1
Vendor - Scope City
Reged: 06/24/03
Posts: 10954
Loc: Los Angeles
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May I presume this was an observatory with a roll-off roof? 
No fair taking measurements indoors!
Seriously, though, record those measurements on the SQM database: HERE.
But don't be too surprised if a lot of Cloudy Nighters move next door!
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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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SaberScorpX
Post Laureate
Reged: 01/12/05
Posts: 4121
Loc: illinois, usa
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Just curious, Don.
When is the Zenith not 'Up'? 
Stephen Saber
PAC/Astronomical League
http://www.geocities.com/saberscorpx/home.html
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Tom Polakis
professor emeritus
Reged: 12/20/04
Posts: 551
Loc: Tempe, Arizona
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Quote:
Seriously, though, record those measurements on the SQM database: HERE.
What I would really like to see would be a light pollution map of the U.S. -- or better yet, detailed large-scale maps -- with SQM readings overlaid. If the data showed that the light pollution model is calibrated, you would know ahead of time exactly what to expect for sky brightness.
But the data shows that the model may need some tweaking. For example, the SQM readings show that Magdalena Ridge may be represented unfavorably by the model, as it is not in the black zone despite SQM readings approaching 22.
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Tom Polakis
Tempe, AZ
Visual observing, DSLR photography, lunar & planetary imaging
http://www.pbase.com/polakis/
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Starman1
Vendor - Scope City
Reged: 06/24/03
Posts: 10954
Loc: Los Angeles
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Tom,
Yeah. That's why it's so important to file your readings with the Unihedron SQM database--both the "typical" readings and the darkest ones. Ideally, a "contour map" of the US with dark sky readings could be created.
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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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Tony Flanders
Carpal Tunnel
Reged: 05/18/06
Posts: 2096
Loc: Cambridge, MA, USA
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Quote:
Last night--in my new observatory built by Backyard Observatories: SQM readings: 21.78 ( as bad as it ever got) to 22.00 ( the best it recorded).
I bet the sky is partially obstructed there. Data from other observers indicates that a properly calibrated SQM will never get down to 22 under a clear, unobstructed sky. But I've found that even a single tall tree near my observing site can add 0.1 mag to the SQM's reading. Remember that though its sensitivity decreases off-axis, it can, to a very limited extent, "see" down to 10 or 20 degrees above the horizon.
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Tony Flanders
eyeglasses
6x15 and 8x32 monoculars
8x25, 7x35, 10x30 IS, 10x50, and 15x70 binoculars
70mm and 100mm achromatic refractors
4.5", 7", and 12.5" Dobs
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