[AZ-Observing] Observing site (in plain text)
- From: L Knauth <Knauth@xxxxxxx>
- To: AZ-Observing@xxxxxxxxxxxxx
- Date: Mon, 09 Jan 2006 21:59:42 -0700
I understand that the Sentinel site is becoming problematical for some =
of you and that the search is on for additional winter dark sky sites in =
southwest Arizona. I have been observing for many years at a site =
several miles northwest of the Hovatter Exit on I-10 and have been =
joined there in recent years by several members of SAC and EVAC. We =
find this to be an exceptional site with regard to dark skies, safety, =
convenience, and isolation. The area is in a broad topographic saddle =
(1450=92) and is well above the adjacent valley floors. It consists of =
empty desert pavements of various sizes scattered over a 1/8 X 1/2 mile =
area partitioned by mesquite, palo verde, creosote, and a few saguaros. =
It is quite a beautiful Sonoran Desert pediment and is on BLM land. =
Those looking for a good dark sky site are invited to give it a try. It =
is too far away for star parties and probably not suitable for large =
events like the Schwaar Star Gaze, but it is an outstanding site for =
individuals and small groups.
Like all sites, it has advantages and disadvantages.
Advantages:=20
1. Very dark sky as it goes these days in Arizona. Much of the Phoenix =
light dome is blocked by hills and mountains to the east. It does not =
get the direct blast as at Sentinel. The zodiacal band is readily =
visible, usually across the whole sky. We were even able to see the =
light echo in Monoceros a few years back in my 12.5=94.
2. It is a straight shot out I-10 to the Hovatter exit and then a few =
miles of well- graded roads involving two turnoffs. The last =BC to =BD =
mile is a somewhat gravelly, narrow, desert track, although one could =
drive a Mercedes along it with no problem. There are abundant observing =
areas starting within the first =BC mile of the turnoff track; we go in =
about =BD mile.
3. Traffic on the nearest dirt road is very rare. We cannot be seen =
easily from this road.
4. The southern horizon has a mountain about a mile away that doesn=92t =
project as high as the cinder cone at Sentinel. On nights of =
exceptional transparency and steady seeing, I often look at Australian =
deep sky objects.=20
5. The seeing can get rock solid, although this happens less than =BD =
the time. It is routine to be able to use >250 X at various times =
during an average night. It was really good December 27, with a view of =
Saturn on the zenith I will never forget. I was also able to use a 3mm =
eyepiece with a Barlow on the eskimo planetary nebula as it culminated, =
a sight that was truly astounding. We have never encountered seeing of =
10/10, but 8/10 with flashes of higher values can occur there. =
Transparency can get as good as any SW Arizona site.
6. This place appears to be about as safe as it can get. There is no =
chance of border traffic here. There is no vehicular through-traffic at =
night since the track dead-ends for normal vehicles just to the north of =
our place. I have observed alone there many times and always feel =
totally safe and comfortable. No one without a telescope has ever come =
up the track at night.
7. The site has a variety of desert plants, a nearby arroyo, and is =
quite attractive. It is a large area with many good places to set up. =
Those who get claustrophobic in tight groups can locate away from the =
pack easily.
8. The area is elevated relative to the adjacent valleys and well above =
the ground haze and dust you often get in western AZ.
Disadvantages:
1. Depending upon where you set up, there is a direct, distant view of =
headlights on a short stretch of I-10 and the truck-stop lights at the =
Vicksburg turnoff. The vehicle lights are inconsequential, but the =
truck-stop lights (2 of them almost coalesced) are about as bright as =
Venus. I set up where a bushy mesquite tree blocks all this and only =
see the distant lights when I walk away from the telescope area. All =
these lights are well below horizon level, so it is easy to find a near =
or distant row of vegetation that totally blocks all. Many areas, =
however, give you a straight view. My colleagues don=92t seem to mind =
these lights and often pay little attention to locating where vegetation =
blocks all. In any case, the lights are not destroyers of night vision =
and do not affect the sky brightness. The freeway noise is sometimes =
just audible as a distant hum, especially in cold weather. A big =
mountain is between the site and I-10 and blocks nearly all the noise.
2. There is some through-going ATV traffic along the track and the =
turnoff road during the day (only). We see maybe a half dozen every =
weekend, usually in one or two groups. They just drive past with a =
wave. The track has become well-defined in the past couple of years by =
ATV traffic. Rarely, one of the riders will come over to see what we =
are doing. It is usually an oldfart snowbird from Quartzite. I believe =
that this is a remote route in the ATV guidebooks. People are usually =
on a drive and not out screwing around the way the worst of them do. So =
far, the ATV traffic has come from distant sources, either Quartzite, =
Salome-Where-She-Danced, or an evolving campsite a few hundered yards =
north of the Hovatter exit (never seen more than 3 camper trailers =
there, though). We are not bothered by this very minimal ATV traffic, =
but you never know what the next weekend might bring!
3. For 2 winter seasons there was a squatter with a trailer for a =
couple of months about =BC mile from where we observe. I never saw him =
and he hasn=92t been back in the past several years. Could happen =
again, but this one had no lights at all and just seemed to be some =
snowbird who wanted solitude.
4. The drive to the turnoff track is really dusty, but the roads are =
wide and usually smooth.=20
5. Anyone who doesn=92t like desert pavement and prefers softer ground =
will not like it here. Some of the pavement areas are a little rocky, =
but there are also broad areas where it is small chips in a nice mosaic. =
The black desert pavement warms up during the day. This is great in =
the winter, but one September afternoon gave us a taste of hell. There =
is not much in the way of shade on the pavements, so you need cover =
during the day. This is not a summer site unless you leave by 10 am the =
next morning. I have enjoyed one-nighters there as late as early June. =
Two-nighters are possible as early as September, depending.
6. This site is 95 miles west of the I-10/I-17 stack. It is not good =
for same-night return. It takes me about 2 hours 30 minutes to get from =
my house in northeast Mesa, but I am pulling a trailer, have to cross =
downtown Phoenix, usually stop at the old Rip Griffen truck stop to =
experience highway Americana, and go slowly over the dirt roads.=20
7. Astrophotographers may be bothered by the jet traffic departing west =
out of Sky Harbor. Until about midnight, there is significant high =
altitude air traffic overhead. There is no problem with jet noise or =
interference with visual observing. Occasionally, low-flying military =
aircraft pass nearby during the day. No bombs or flares ever.
8. Weekend gunshots are heard on rare occasions, usually way distant =
over the hill to the east. One user did report some closer activity =
recently. So far, this has not been a problem.
So, there is a description as best I can do. We welcome anyone who =
wants to give the place a try, but we do ask a few things because this =
site means a great deal to us:
a. Please: no radios, white lights, generators, smoking near or upwind =
of the telescopes, running car engines all night to keep warm, or music =
through speakers (bring those headphones!). The ambience of the cosmos =
over the deep Arizona desert is a treasure and is part of the experience =
we go out there for. The area is very clean and we hope it stays that =
way.
b. I would appreciate an e-mail if you know in advance you are coming =
out on weekends near new moon. You don=92t need to bother, but I am =
usually there and like to have some idea of who might be coming out. =20
c. Until you get familiar with your favorite observing spot, please =
arrive before sundown so that you don=92t have to reconnoiter around =
with headlights.
d. I have a favorite spot optimal for my telescope-trailer =
configuration and such. Please let me have it!! It=92s all public =
land, but I ask a favor here.
e. Those planning a nighttime departure should locate along the =
southern periphery. This would cause minimal disruption.
f. Full-up 5 mw green lasers work just fine at this dark sky site but =
should be used sparingly. The illegal higher power ones should not be =
used here for 3 safety reasons: 1) accidental turn-ons and unintended =
reflections can cause serious eye damage to others, 2) the beams are =
highly visible and could draw unwelcome visitors, 3) accidental =
interception of over-flying aircraft is more likely here because of the =
enhanced high-altitude traffic.
You can see the desert pavement and a view southeast from our site at: =
http://www.public.asu.edu/~iaclpk/telescope.htm
Bill Van Orden (aka =93Beevo=94) has some shots at: =
http://beevo.com/star_parties.htm (scroll down to =93December new moon =
weekend=94)
Here are coordinates and driving directions. This takes you to the =
little area where we currently set up. There are lots of areas in the =
=BC mile south and southwest of this place as well.
Directions from Phoenix:
West on I-10 to Hovatter Exit. North 1.8 miles, take turnoff to left =
(at N 33 deg 38.324m; W 113 deg 36.766m). West 2.3 miles to =
cattleguard (N 33d 39.083; W 113d 38.785m). Turn right after crossing =
cattle guard (as in start your turn while exiting the cattle guard). =
Good observing sites begin on the left as soon as you pass where a track =
takes off to the west. Our little spot is about =BD mile north of the =
cattle guard at (N 33d 39.570m; W 113d 38.629m).
Let me know if you have any questions. I hope to meet some of you out =
there in the future.
Sincerely,
Paul
Paul Knauth
Department of Geological Sciences
(to become School of Earth and Space Exploration 7/1/06)
Arizona State University
Tempe, AZ 85287-1404
480-965-2867 (voice)
480-654-4159 (home)
http://www.public.asu.edu/~iaclpk/
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