[AZ-Observing] Observing site in western Arizona

[L Knauth <Knauth@xxxxxxx>]

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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[AZ-Observing] Observing site in western Arizona