  We study the pair creation of point-particles and strings in a
time-dependent, weak gravitational field. We find that, for massive string
states, there are surprising and significant differences between the string and
point-particle results. Central to our approach is the fact that a weakly
curved spacetime can be represented by a coherent state of gravitons, and
therefore we employ standard techniques in string perturbation theory. String
and point-particle pairs are created through tree-level interactions between
the background gravitons. In particular, we focus on the production of excited
string states and perform explicit calculations of the production of a set of
string states of arbitrary excitation level. The differences between the string
and point-particle results may contain important lessons for the pair
production of strings in the strong gravitational fields of interest in
cosmology and black hole physics.
