  We will utilize the sensitivity of SIRTF through the Legacy Science Program
to carry out spectrophotometric observations of solar-type stars aimed at (1)
defining the timescales over which terrestrial and gas giant planets are built,
from measurements diagnostic of dust/gas masses and radial distributions; and
(2) establishing the diversity of planetary architectures and the frequency of
planetesimal collisions as a function of time through observations of
circumstellar debris disks. Together, these observations will provide an
astronomical context for understanding whether our solar system - and its
habitable planet - is a common or a rare circumstance. Achieving our science
goals requires measuring precise spectral energy distributions for a
statistically robust sample capable of revealing evolutionary trends and the
diversity of system outcomes. Our targets have been selected from two carefully
assembled databases of solar-like stars: (1) a sample located within 50 pc of
the Sun spanning an age range from 100-3000 Myr for which a rich set of
ancillary measurements (e.g. metallicity, stellar activity, kinematics) are
available; and (2) a selection located between 15 and 180 pc and spanning ages
from 3 to 100 Myr. For stars at these distances SIRTF is capable of detecting
stellar photospheres with SNR >30 at lambda < 24 microns for our entire sample,
as well as achieving SNR >5 at the photospheric limit for over 50% of our
sample at lambda=70 microns. Thus we will provide a complete census of stars
with excess emission down to the level produced by the dust in our present-day
solar system. More information concerning our program can be found at:
http://gould.as.arizona.edu/feps
