  A degree one del Pezzo surface is the blowup of P^2 at 8 general points. By
the classical Cayley-Bacharach Theorem, there is a unique 9th point whose
blowup produces a rational elliptic surface with a section. Via this
relationship, we construct a stable pair compactification of the moduli space
of anti-canonically polarized degree one del Pezzo surfaces.
