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 :


TSE2008: 01 August 2008 Total Solar Eclipse:
A Flight into the Darkness of the Lunar Umbral Shadow
G. Schneider, University of Arizona

SEC 2007 (Unofficial) Group Photograph - Courtesy of Andrew White