  The fields of occultation and microlensing are linked historically. Early
this century, occultation of the Sun by the Moon allowed the apparent positions
of background stars projected near the limb of the Sun to be measured and
compared with their positions six months later when the Sun no longer
influenced the light path to Earth. The measured shift in the stellar positions
was consistent with lensing by the gravitational field of the Sun during the
occultation, as predicted by the theory of general relativity. This series of
lectures explores the principles, possibilities and challenges associated with
using occultation and microlensing to discover and characterize unseen planets
orbiting distant stars. The two techniques are complementary in terms of the
information that they provide about planetary systems and the range of system
parameters to which they are most sensitive. Although the challenges are large,
both microlensing and occultation may provide avenues for the discovery of
extra-solar planets as small as Earth.
