  Kepler's quest for other Earths need not end just yet: it remains capable of
characterizing cool Earth-mass planets by microlensing, even given its degraded
pointing control. If Kepler were pointed at the Galactic bulge, it could
conduct a search for microlensing planets that would be virtually
non-overlapping with ground-based surveys. More important, by combining Kepler
observations with current ground-based surveys, one could measure the
"microlens parallax" \pi_E for a large fraction of the known microlensing
events. Such parallax measurements would yield mass and distance determinations
for the great majority of microlensing planets, enabling much more precise
study of the planet distributions as functions of planet and host mass,
planet-host separation, and Galactic position (particularly bulge vs. disk). In
addition, rare systems (such as planets orbiting brown dwarfs or black holes)
that are presently lost in the noise would be clearly identified. In contrast
to Kepler's current primary hunting ground of close-in planets, its
microlensing planets would be in the cool outer parts of solar systems,
generally beyond the snow line. The same survey would yield a spectacular
catalog of brown-dwarf binaries, probe the stellar mass function in a unique
way, and still have plenty of time available for asteroseismology targets.
