  Current protoplanetary dust coagulation theory does not predict dry silicate
planetesimals, in tension with the Earth. While remedies to this predicament
have been proposed, they have generally failed numerical studies, or are in
tension with the Earth's (low, volatility dependent) volatile and moderately
volatile elemental abundances. Expanding on the work of Boley et al. (2014), we
examine the implications of molten grain collisions and find that they may
provide a solution to the dry silicate planetesimal problem. Further, the
source of the heating, be it the hot inner disk or an FU Orionis scale
accretion event, would dictate the location of the resulting planetesimals,
potentially controlling subsequent planetary system architectures. We
hypothesize that systems which did undergo FU Orionis scale accretion events
host planetary systems similar to our own, while ones that did not instead host
very close in, tightly packed planets such as seen by Kepler.
