  High-contrast observations in optical and infrared astronomy are defined as
any observation requiring a technique to reveal a celestial object of interest
that is in such close angular proximity to another source brighter by a factor
of at least 10^5 that optical effects hinder or prevent the collection of
photons directly from the target of observation. This is a relatively new type
of observation that enables research on previously obscured parts of the
Universe. In particular, it is most applicable to Comparative Planetary
Science, a field that directly attacks such questions as "how common are
planetary systems? What types of planets exist, and are there planets other
than Earth that are capable of supporting life as we know it?" We survey the
scientific motivations for high-contrast observations, provide an overview of
the techniques currently being used or developed, and discuss some ideas and
studies for future prospects.
