Site-Location Plans for Near-Edge Observations near Winslow, Arizona


The 21-20 May 2012 Annular solar eclipse (ASE 2012) is visible from parts of southeast China (including Macau and Hong Kong soon after sunrise May 21 local time), Taiwan (Taipai near southern limit), Japan (Kagoshima, Osaka, and Tokyo on centerline), across the north Pacific, and the southwest United States (May 20 local time). 

In the SW USA the annular eclipse may be seen northern California, Nevada, southern Utah, northern Arizona, the southwest corner of Colorado, New Mexico, and (at sunset) western Texas.


Eclipse observers traveling into the path of annularity will usually elect to position themselves either (a) on "centerline" (blue line on maps above), (b) just inside the annular path limits (orange lines on maps above), or (c) some locations in between of particular geographical interest.  From centerline (a), the Moon will traverse centrally across the angularly larger solar disk so as to lave a concentric annulus of photospheric light surrounding the moon at mid-eclipse.  From just inside (~ 2 km) the northern or southern limits, the moon's silhouette in front to the Sun at mid-eclipse will have one limb of the Moon internally tangent to the solar limb at mid-eclipse.  From here an extreme "solar crescent" will form with the jagged edge of the moon (from its mountains and valleys in profile) will cause a continually changing pattern beads of sunlight near the point of tangency for ~ 2 minutes centered on mid-eclipse. (Click and HERE and  HERE to see videos of  of near-limit Baily's beads from the May 10, 1994 annular solar eclipse).

Mid-eclipse on Centerline
(near Page, AZ)
Mid-eclipse 2 km inside southern limit
(near Winslow, Arizona)
Limb profile detail at C2 near Winslow, Arizona
(solar North up in this display)
Above graphics generated with Xavier Jubier's "Solar Eclipse Maestro" S/W for MacOS X

Click HERE to see an animation of the progression of the Moon across the Sun for +/- 5 minutes centered on mid-eclipse as will be seen from just north of Winslow, Arizona (as discussed below).

For ASE 2012 the plan is to observe from just inside southern limit to see extended Balily's bead phenomenena with a prolonged C2-to-C3 internaly-tangent transit of the Moon's limb -- not from a centerline location.


In the SW USA, the expectations for lack-of cloud cover are most favorable for northern Arizona, and in particular for the region in and around Winslow - a town which is itself located on the southern limit of the path of annularity.  See below monthly average cloud cover statistics across the path of annularity for May as compiled by Jay Anderson.  See Jay's web site for more information. 

May monthly cloud cover percentage  along the path of annularity - compiled by Jay Anderson.

TAKE IT EASY (click):

Given then the statistically best likelihood for clear skies and the fortuitous (for me) proximity to Tucson (where I am located, only about a 5-1/2 hour drive), the "plan" (modulo near-term weather forecast modification) is to observe ASE 2012 from just north of Winslow, Arizona, 2 km (+/- 0.5 km) north of Southern limit.   From Winslow, eclipse first contact (partial ingress phase) begins at 5:27 PM MST on the evening of Sunday May 20.  Mid-annularity is at 6:36 PM MST, and the sun will set at 7:23 PM in 25% partial eclipse (exact times are given below).

In the annotated satellite photo below, showing the town of Winslow with the southern limit of the path of annularity (red line) running parallel to Interstate-40 and bifurcating the town, the red "X" marks the eclipse-observation spot. 

Winslow, southern limit, and observing location ("X" marks the spot).  North is up.
Click HERE for a larger, higher-reolution photo.

Close-up view of the observing area and local infrastructure.  North is to the right.
Click HERE for a larger, high-resolution photo.


This specific 2-km north of southern limit location was chosen because of:

(a) Logistical Considerations -- SEE detailed map/photo below
     - very close proximity to motels (Econolodge, Motel 6 both ~ 1 mile) and < 2 min drive to observing site
     - very close proximity to (many) restaurants, grocery stores, hardware stores, etc.
     - very easy roadside access to viewing site on a well maintained road (N. Park Rd).
     - uncrowded immediate location devoid of buildings and other obstructions

(b) Viewing and Contingency Considerations
      - apparently unobstructed view in the direction to the eclipse and down to the horizon
      - ample open space for comfortably setting up with immediate road-side parking access
      - immediately proximate to major interstate highway (I-40) "paralleling" southern limit
        (in the event of contingency re-location due to clouds or other circumstances).

See this in Google Maps: Click HERE


Latitude: 35° 03' 07.42" N (+35.05206°),  Longitude: 110° 41' 53.05" W (-110.69807°)
Obscuration at Maximum Eclipse: 87.10%
Magnitude at Maximum Eclipse: 0.93326
Mean-Limb Annular Duration: 44.5 s

ECLIPSE EVENT  MST       Altitude Azimuth  PA    VA  
Contact I:     17:27:11  +21.8°    280.0°   274°  4.8°
Contact II:    18:36:19   +8.2°    289.0°   353°  2.0°
Max-Eclipse:   18:36:41   +8.1°    289.1°     2°  1.8°
Contact III:   18:47:02   +8.0°    289.1°    12°  1.5°
Sunset:        19:24:03   +0.0°    295.0°    N/A  N/A
Contact IV:    Not Visible Below Horizon


Two alternate/contingency sites (shown below), also 2 km north of southern limit with easy access right off I-40 and good eclipse visibility, have been identified 15-17 km west of the primary site north of Winslow, about half-way toward the Barringer METEOR CRATER (which is outside of the path of annularity).  CLICK HERE for a larger, high-resolution photo and photos of the two sites.

THE (current) "PLAN" (From Tucson)

Joel Moskowitz is arriving in Tucson on May 18.  We will be watching the weather (from Tucson) on May 18 and the morning of May 19.  If good weather predictions for northern Arizona hold, we will leave Tucson mid-morning (~ 10 AM or earlier) on Saturday, May 19th, via route 79 to 87 into Winslow.  (If the weather looks bad for northern Arizona on the morning of May 19, but good elsewhere, e.g., New Mexico, we will elect for a "Plan B"). 

The total driving distance to Winslow is 271 miles (from my house or close to the same from my office on UofA campus) with an estimated drive time of 5-1/2 and, so, arrival to the motel in Winslow at or before about 4 PM.  This will give us ample time to check out the prime and alternate observing sites (or others, if any, to relax at the hotel) at or before sunset on May 19 with then dinner and an overnight stay in Winslow.

Joe, Renate, and Maria Rao awill fly into Phoenix on Saturday May 19th, and drive up to Winslow to join us either on the morning of the 20th. 

Jay, Melissa, and Beno Friedland will be flying into Phoenix on the morning (late morning) on eclipse day, Sunday May 20 and will meet up with us in the early/mid afternoon in Winslow (it's about a 3-1/2 hour drive from Phoenix to Winslow) or (if early enough) at the Meteor crater (see below).

After breakfast on the morning of May 20 (eclipse day), we will drive to the Barringer Meteor crafter (about 25 miles from the motel in Winslow) for moring/early afternoon siteseeing (see the meteor crater WEB SITE). We'll then have a mid-afternoon lunch near the hotel and then set up for the eclipse.  1st contact to sunset (after annularity) is 5:27PM - 7:24PM local (MST) time.

Joel has a 9:15 AM MST flight out of Tucson on Monday morning May 21, so we will be leaving Winslow right after the eclipse to drive back to Tucson.   It should not take long at all to put cameras etc. back in the car, grab a quick dinner down the road from the eclipse site and be on the way back to Tucson by no later than 8 PM with an arrival back into Tucson by 1:30 AM. 

 -- Glenn Schneider.  Last update 29 March 2012