Theoretical and Observational Problems Related to Solar Eclipses (NATO Science Series C

The contributions to this work are based on late-1990s knowledge of solar corona physics and on the prospects for future total eclipse observations, focusing on the eclipse of August 11, 1999 - the last this century - which forecasters believe will occur at precisely the maximum of solar activity. The results of past eclipse observations are reviewed, including coronal hot and cold structures, coronal heating, public education and instrumental problems. The relation of the corona to the Sun is discussed, that is, the energy and mass transfer between the chromosphere and the corona, including the formation of prominences by coronal condensation in coronal cavities and the supply of mass to the corona by spicules. The coronal heating mechanism is also discussed, that is, does heating occur in current sheets or in sheaths surrounding flux tubes? Prospects for international collaborative observations, both ground-based and from space, are presented.