  Yiannis Sakellaridis and Akshay Venkathesh have determined, when the group
$G$ is split and the field $\F$ is of characteristic zero, the Plancherel
formula for any spherical space $X$ for $G$ modulo the knowledge of the
discrete spectrum.
  The starting point is the determination of good neighborhoods at infinity of
$X/J$, where $J$ is a small compact open subgroup of $G$. These neighborhoods
are related to "boundary degenerations" of $X$. The proof of their existence is
made by using wonderful compactifications.
  In this article we will show the existence of such neighborhoods assuming
that $\F$ is of characteristic different from 2 and $X$ is symmetric. In
particular, one does not assume that $G$ is split. Our main tools are the
Cartan decomposition of Benoist and Oh, our previous definition of the constant
term and asymptotic properties of Eisenstein integrals due to Nathalie Lagier .
  Once the existence of these neighborhoods at infinity of $X$ is established,
the analog of the work of Sakellaridis and Venkatesh is straightforward and
leads to the Plancherel formula for $X$.
