LTU/Airberlin Airlines | Deutsche Polarflug | Sky & Telescope | TravelQuest International |
Eclipse Flight
Technical Planning by Dr.
Glenn Schneider, Steward Observatory, University of Arizona |
DEPLOYMENT/RELOCATION FLEXIBILITY To Find the BEST Spot in the Area of Operations for Observing |
CLOUD OBSCURATION AVOIDANCE Polar Summer Stratosphere: 99.99% -- Virtually Assured |
TOTALITY PROLONGATION Aircraft Speed Extends the Duration of Totality |
SKY TRANSPARENCY Significantly Improved -- Low Particulate Scattering |
SKY DARKNESS Much Higher Contrast Coronal Visibility and to Larger Distance |
IMPROVED ASTRONOMICAL SEEING "r_naugh" Decreases with Increasing Altitude |
REDUCED ATMOSPHERIC TURBIDITY Vorticity & Sheer Decline in Power Above Tropopause |
PANCHROMATIC
VISIBILITY IR and UV "Windows" Open Up or are Extended |
UNPARALLELED HORIZON REACH &
OBSERVATION VISTA Apparent horizon 377 km distant, depressed 3.4° (at 37,000 ft) |
ESTHETIC, ETHEREAL EXPERIENCE There is nothing quite like it... |
IN THE MOON'S SHADOW AT 35.000
FEET
|
The view of a total solar eclipse, and the sweep of the Moon's umbral shadow as it races across (and above) the Earth as seen from such a lofty height, is magnificent. As seen from 37,000 feet above the surface of the Earth, the apparent horizon is 377 km (234 miles) away and depressed by 3.4° compared to sea level. As shown in the accompanying photographs (top by C. Roberts ~ 1 minute before and after totality, bottom by J. Pasachoff at mid-eclipse) taken from the 23 November 2003 eclipse flight at 35,000 feet at a latitude of 70° S: — The high reflectivity of the polar ice below accentuates the stark contrast between the eclipse-darkened regions within umbral shadow, and those illuminated by the Sun beyond the shadow's periphery. — Looking along the apex of the lunar umbral cone, toward the eclipsed Sun at mid-totality, the curvature of the distant umbral shadow boundary (i.e., the "shadow ellipse") is readily apparent. The 01 August 2008 Arctic/polar eclipse flight provides an unparalleled opportunity to observe the upcoming eclipse under the very favorable, and remarkably similar, conditions as prevailed for the 23 November 2003 Antarctic eclipse flight. For TSE2008 the Sun will be at a somewhat higher altitude, 25° above the horizon vs. 15° (as in these photographs), and the eclipse will be viewed closer to the Earth's rotational pole than any total solar eclipse in history. |
This, likely, is the most frequently asked question from those with ground-based eclipse observing experience. The answer (in an aircraft with suitable windows) is unequivocally YES. This was recently demonstrated with spectacular results from images taken by D. Finally (an eclipse-viewing passenger on the 23 November 2003 QF2901 Antarctic eclipse flight) through one of the main cabin windows as processed by M. Druckmuller (see image to right). The 22x32 cm cabin windows of the Airbus A330-200 aircraft have been inspected and are of good optical quality and equally well suited for eclipse observations. Our aircraft provider (LTU/Airberlin) is well aware of the cleanliness requirements for the windows on the TSE2008 flight, and will deliver the aircraft for preparation to our detailed specifications the evening before the eclipse. The placement and cadence of the windows with respect to each of the two-seat sun-side seat rows has been checked for accessibility from the adjacent seats (the few seat rows without suitable window access will not be used). Individuals can assess (from inspection photographs on the TravelQuest web site which are available) whether share or exclusive window access suits their needs. |
"Can I really observe coronal detail through an airplane window?" |
SVALBARD |
The
likelihood of a delayed take-off from Dusseldorf at 6 AM in
the
morning is exceedingly small. None-the-less, the eclipse intercept has
not been planned with a time-critical take-off. The
inclusion of "extra" time aloft, before the time-critical intercept
with the Moon's shadow, is a necessary
and prudent contingency to safeguard against the unlikely event of a
take-off delay. In doing so we make the most
effective use
of requisite contingency scheduling "dead time" by augmenting the
flight plan with spectacular value-added sightseeing opportunities over
these geographically fascinating terrains. These "flightseeing" segments are not specifically tied to the eclipse observations. The flight plan is baselined with pre-eclipse low-altitude flightseeing segments over Longyearbyen/Svalbard and a post-eclipse fly-over and circumnavigation of the geographic North Pole. Click HERE to see the flight plan segment ordering that allows us to use the approximately an hour of pre-planned low-altitude (7,000 ft.) flightseeing time as a buffer against a "late" take-off and still achieve an optimized mid-eclipse intercept. One, or both, of the flightseeing segments could be executed following the "totality run", if that contingency should prove necessary. |
NORTH POLE |
In the Area of Operations, the duration of
totality will be increased by appx. 40s over the “ground"... |
...with the Sun comfortably positioned and
optimally oriented for observations on the starboard side of the
aircraft. |
Figure 1. Ground and Air Durations of Totality |
Figure 2. Solar Elevation at Mid-Eclipse |
Following
the Spitzbergen (Svalbard) siteseeing leg, our aircraft will
climb from 7,000 ft to 37,000 ft. to a pre-positioning point (WP1) at
80°N, 5°E, 145.4 nm ground-track distance from the start of the
"Totality Run". At
that point we will execute a shallow heading alignment maneuver
designed to bring us to a point of planned mid-course correction (WP2)
44.8
nm from the start of the totality run. During this 145.4
nm of flight approaching the totality run, we will adjust the
aircraft's speed and direction of flight, as necessary, to assure a
high-precision arrival in time and space to begin the Totality Run 10
minutes before mid-eclipse. Upon arrival at the Totality Run start point, we will place the aircraft on a heading so that at Mach 0.85 (483 nm/hr) it will cross centerline (at 37,000 ft. while flying "straight and level") at the instant that the aircraft is centrally located within the footprint of the Moon's (moving) umbral shadow and, oriented so the Sun appears "straight out" the cabin windows (i.e., perpendicular to the direction of flight). Thus, the heading of the aircraft will be that of the solar azimuth at the point of mid-eclipse intercept minus 90 degrees. The Totality Run will commence prior to second contact, nominally *10* minutes before mid-eclipse (~ 8.4 minutes before second contact). Our pre-positioning leg will terminate with a small heading realignment maneuver to place the aircraft at the Totality Run Start point and at the requisite time, heading and speed so the aircraft will be centrally located in the umbral shadow at the instant of mid-eclipse. No change in aircraft heading (orientation) or altitude would be planned once the Totality Run begins. The aircraft will turn onto the Totality Run track sufficiently far ahead (in time) of second contact to allow observers to acquire the Sun in photographic equipment, and watch the last part of the partial eclipse ingress while the Sun appears as a thin crescent. Here, the completion of the heading re-alignment maneuver is planned to place the aircraft at the Totality Run "Start point" 10 minutes before mid-eclipse (appx 8m 20s minutes before second contact). The aircraft will remain on this heading for at least 3 minutes after mid-eclipse (i.e., appx 1m 35s after third contact {or longer at pilot's discretion}), before turning the due north for a post-eclipse overflight and circling of the North geographic pole. |