  We characterize the Majorana zero modes in topological hybrid
superconductor-semiconductor wires with spin-orbit coupling and magnetic field,
in terms of generalized Bloch coordinates $\varphi, \theta, \delta$, and
analyze their transformation under SU(2) rotations. We show that, when the
spin-orbit coupling and the magnetic field are perpendicular, $\varphi$ and
$\delta$ are universal in an appropriate coordinate system. We use these
geometric properties to explain the behavior of the Josephson current in
junctions of two wires with different orientations of the magnetic field and/or
the spin-orbit coupling. We show how to extract from there, the angle $\theta$,
hence providing a full description of the Majorana modes.
