Presented at the 3rd
International Solar Eclipse Conference
Griffith Observatory, Los Angeles, CA. 23 August 2007
Click HERE
to download the conference presentation material
(originally PowerPoint, converted to PDF; 66 Mb)
ABSTRACT: We have been graced
by the fortuitous coincidence of having a naturally occurring
near-spherical, opaque, Earth-orbital occulter (the Moon) with an
angular diameter ≈1/400th Sun s at an average geocentric distance of
1/400 solar diameters. Thus, at infrequent and fleeting moments the
solar photosphere is obscured as seen by Earth-bound observers at the
"right" place and time during a Total Solar Eclipse. Majestically, the
solar chromosphere and corona are unveiled with the advent of a dark
"sunless" daytime sky -- unless clouds get in the way of those
circum-solar photons in their last 0.000007% of their travels! To
mitigate the risk of such an unwanted occurrence, eclipse observers
have taken to the skies to locate themselves in the rarefied layers of
the Earth’s atmosphere above offending, optically thick, clouds.
High-flying "umbraphiles" have done so not only obviate concerns of
cloud cover, but to prolong the obtainable duration of totality (and in
one extremely marginal case to create an otherwise elusive "t"otality)
while exploiting the significantly darker than ground-level sky
background thereby greatly enhancing coronal-to-sky contrast.
Other factors beyond the near-guarantee of clear skies such as
exceptional infra-red transparency, greatly reduced atmospheric
turbidity, extremely low aerosol scattering from airborne particulates
along the line-of sight to the Sun, and improved natural "seeing" have
motivated airborne eclipse chasing. This talk highlights nearly a
century of airborne eclipse chasing from the historical, scientific,
and (more recent) personal perspective of the presenter. From bi-planes
to Concordes, in pressure suits and with fine-dining in first class,
chasing the lunar umbral shadow has taken new dimensions of challenges
when perused into the stratosphere and beyond for science, for esthetic
wonderment, and — just for the fun of it.
PRESENTER BIOGRAPHY: Dr. Glenn Schneider is an Associate Astronomer at
University of Arizona’s Steward Observatory where, since 1994, he has
served as the Project Instrument Scientist for the Hubble Space
Telescope’s Near Infra-red Camera and Multi-Object Spectrometer. His
research and instrumental interests are primarily centered on the
formation, evolution, and characterization of extrasolar planetary
systems, and high contrast space-based (coronagraphic) imaging systems.
His studies have focused on the direct detection of sub-stellar and
planetary mass companions to young and near-by stars and the
circumstellar environments from which such systems may arise and
interact. In concert with his scientific investigations of
circumstellar dust and debris disks and co-orbital bodies they may
harbor, he has played a leading role in the development of very high
contrast space-based coronagraphic and near-infrared imaging systems
and techniques with HST, leading to spatially resolved scattered light
images the birthplaces of planetary systems. Dr. Schneider is a member
of the International Astronomical Union’s Working Group on Solar
Eclipses with expertise in the high-precision numerical calculation of
eclipse circumstances and the application of those computations in
planning and carrying out observations of total solar eclipses. For
more than three decades, Dr. Schneider has lead expeditionary groups
and conducted such observations on land, sea and air of twenty-six
total solar eclipses occurring since 7 March 1970 from remote locations
across the globe conducting direct, polarimetric, and
spectrophotometric imaging programs. Additionally, he has executed
three, and planned seven, high-altitude eclipse intercepts with jet
aircraft and is now preparing for his next stratospheric eclipse
flight, for TSE 2008, at 82 degrees North latitude. Additional
information on his background and research interests may be found at :
http://nicmosis.as.arizona.edu:8000/
