  In this article we address a number of features of the moduli space of
spherical metrics on connected, compact, orientable surfaces with conical
singularities of assigned angles, such as its non-emptiness and connectedness.
We also consider some features of the forgetful map from the above moduli space
of spherical surfaces with conical points to the associated moduli space of
pointed Riemann surfaces, such as its properness, which follows from an
explicit systole inequality that relates metric invariants (spherical systole)
and conformal invariant (extremal systole).
