  We study the joint probability distributions of separation, $R$, and radial
component of the relative velocity, $V_{\rm R}$, of particles settling under
gravity in a turbulent flow. We also obtain the moments of these distributions
and analyze their anisotropy using spherical harmonics. We find that the
qualitative nature of the joint distributions remains the same as no gravity
case. Distributions of $V_{\rm R}$ for fixed values of $R$ show a power-law
dependence on $V_{\rm R}$ for a range of $V_{\rm R}$, exponent of the power-law
depends on the gravity. Effects of gravity are also manifested in the following
ways: (a) moments of the distributions are anisotropic; the degree of
anisotropy depends on particle's Stokes number, but does not depend on $R$ for
small values of $R$. (b) mean velocity of collision between two particles is
decreased for particles having equal Stokes numbers but increased for particles
having different Stokes numbers. For the later, collision velocity is set by
the difference in their settling velocities.
