The primary goal of PLATO is to open a new way in exoplanetary
science, by providing a full statistical analysis of
exoplanetary systems around stars that are bright and nearby
enough to allow for simultaneous and/or later detailed studies
of their host stars. The possibility of observing this sample of
host stars with a photometric precision of 1ppm will allow a
seismic analysis leading to determination of stellar and
planetary masses of around 1%. Ages of the systems will be
possible to determine to within several hundred million years
allowing for an order of magnitude increase in our knowledge of
planetary and stellar evolution. The mission will also observe a
very large number of stars to a slightly lesser precision. All
of this will lead to the extending by an order of magnitude the
knowledge of exoplanetary systems and their host stars initiated
with CoRoT and followed up with Kepler, by surveying many more
stars down to a magnitude allowing for the detection of Earth-
sized planets. As a secondary impo