Abstract: We prove some results about the singularities of Satake compactifications of classical moduli spaces, this will give an insight into the relation among solutions of the Schottky problem in different genera. The moduli space $A_g$ lies in the boundary of $A^S_{g+m}$ for every $m$. We will show that the intersection between $M^S_{g+m}$ and $A_g$ contains the $m$-th infinitesimal neighbourhood of $M_g$ in $A_g$, this implies that stable equations for $M_g$ do not exist. In particular, given two inequivalent positive even unimodular quadratic forms P and Q, there is a curve whose period matrix distinguishes between the theta …