<P> A total solar eclipse provides a rare opportunity to observe the corona (the outer layer of the Sun's atmosphere). Normally this is not visible because the photosphere is much brighter than the corona . According to the point reached in the solar cycle, the corona may appear small and symmetric, or large and fuzzy . It is very hard to predict this in advance . </P> <P> As the light filters through leaves of trees during a partial eclipse, the overlapping leaves create natural pinholes, displaying mini eclipses on the ground . </P> <P> Phenomena associated with eclipses include shadow bands (also known as flying shadows), which are similar to shadows on the bottom of a swimming pool . They only occur just prior to and after totality, when a narrow solar crescent acts as an anisotropic light source . </P> <P> The observation of a total solar eclipse of May 29, 1919, helped to confirm Einstein's theory of general relativity . By comparing the apparent distance between stars in the constellation Taurus, with and without the Sun between them, Arthur Eddington stated that the theoretical predictions about gravitational lenses were confirmed . The observation with the Sun between the stars was only possible during totality since the stars are then visible . Though Eddington's observations were near the experimental limits of accuracy at the time, work in the later half of the 20th century confirmed his results . </P>

When did the last eclipse of the moon occur