  We explore the possibility of discovering the mirror baryons and electrons of
the Mirror Twin Higgs model in direct detection experiments, in a scenario in
which these particles constitute a subcomponent of the observed DM. We consider
a framework in which the mirror fermions are sub-nano-charged, as a consequence
of kinetic mixing between the photon and its mirror counterpart. We consider
both nuclear recoil and electron recoil experiments. The event rates depend on
the fraction of mirror DM that is ionized, and also on its distribution in the
galaxy. Since mirror DM is dissipative, at the location of the Earth it may be
in the form of a halo or may have collapsed into a disk, depending on the
cooling rate. For a given mirror DM abundance we determine the expected event
rates in direct detection experiments for the limiting cases of an ionized
halo, an ionized disk, an atomic halo and an atomic disk. We find that by
taking advantage of the complementarity of the different experiments, it may be
possible to establish not just the multi-component nature of mirror dark
matter, but also its distribution in the galaxy. In addition, a study of the
recoil energies may be able to determine the masses and charges of the
constituents of the mirror sector. By showing that the mass and charge of
mirror helium are integer multiples of those of mirror hydrogen, these
experiments have the potential to distinguish the mirror nature of the theory.
We also carefully consider mirror plasma screening effects, showing that the
capture of mirror dark matter particles in the Earth has at most a modest
effect on direct detection signals.
