  The two Terrestrial Planet Finder (TPF) missions aim to perform spectroscopy
on extrasolar Earths; TPF-C will operate in visible light, and TPF-I will
operate in the mid-infrared. Extrasolar Earths are assumed to be roughly 26
magnitude in V band, roughly 0.3 microJy in the mid-IR, and located as close as
roughly 30 milliarcseconds from a reasonable set of target stars, demanding
high sensitivity, angular resolution and dynamic range to study. With
capabilities matched to this task, the TPF missions could easily undertake a
broad range of further scientific investigations. This document discusses the
potential of TPF for general astrophysics and comparative planetology beyond
its base mission, focusing on science obtainable with no or minimal
modifications to the mission design, but also exploring possible modifications
to TPF with high scientific merit and no impact on the basic search for
extrasolar Earth analogs. It addresses both TPF-C and TPF-I, but emphasizes
TPF-C, because its launch is planned for 2015, while TPF-I s nominal launch
date is in 2019. This document does not attempt to describe all of the
astrophysics TPF will be capable of, only to present some highlights of a
meeting held at Princeton University, April 14 15, 2004, and some discussions
that followed from that meeting.
