  Natural (such as lunar) occultations have long been used to study sources on
small angular scales, while coronographs have been used to study high contrast
sources. We propose launching the Improved Resolution and Image Selection
(IRIS) Satellite, a large steerable occulting satellite. IRIS will have several
advantages over standard occulting bodies. IRIS blocks up to 99.97% of the
visible light from the occulted point source. Because the occultation occurs
outside both the telescope and the atmosphere, seeing and telescope
imperfections do not degrade this performance. If placed in Earth orbit,
integration times of 250-2500 \second can be achieved over 95% of the sky, from
most major telescope sites. Alternatively, combining IRIS with a basic 2-m (or
4-m) space telescope at the Earth-Sun L2 point could yield longer integration
times and simplified orbital dynamics. Applications for IRIS include searching
for planets around nearby stars, resolution of micro-lensed LMC and Galactic
bulge stars into distinct image pairs, and detailed mapping of solar system
planets from the ground. Using ground-based K-band observations, a Jovian
planet with a surface temperature of 400 \kelvin or Venus at 700 \kelvin could
be imaged at all angular separations greater than about $0.35\as$ out to over
$10\parsec$. Space based observations in the K-band (in emission) or B-band (in
reflection) could do better. Resolution of microlensed stars would greatly
improve our understanding of the Massive Compact Halo Objects (MACHOs)
responsible for observed microlensing events and comprising 20-90% of the mass
of our galaxy.
