  The heliosphere is the magnetic structure formed by the Sun's atmosphere
extending into the local interstellar medium (ISM). The boundary separating the
heliosphere from the ISM is a still largely unexplored region of space. Even
though both Voyager spacecraft entered the local ISM and are delivering data,
they are two points piercing a vast region of space at specific times. The
heliospheric boundary regulates the penetration of MeV- GeV galactic cosmic
rays (CR) in the inner heliosphere. Interstellar keV neutral atoms are crucial
to the outer heliosphere since they can penetrate unperturbed and transfer
energy to the solar wind. Missions such as NASA's IBEX and Cassini are designed
to detect neutral atoms and monitor charge exchange processes at the
heliospheric boundary. The heliosphere does not modulate the TeV CR intensity,
but it does influence their arrival direction distribution. Ground-based CR
observatories have provided accurate maps of CR anisotropy as a function of
energy in the last couple of decades. Combining observations to produce all-sky
coverage makes it possible to investigate the heliosphere's impact on TeV CR
particles. We can numerically calculate the pristine TeV CR distribution in the
local ISM with state-of-the-art heliosphere models. Only by subtracting the
heliospheric influence is it possible to use TeV CR observations to infer
propagation properties and the characteristics of magnetic turbulence in the
ISM. Numerical calculations of CR particle trajectories through heliospheric
models provide a complementary tool to probe the boundary region properties. A
program boosting heliospheric modeling with emphasis on the boundary region and
promoting combined CR experimental data analyses from multiple experiments
benefits CR astrophysics and provides additional data and tools to explore the
interaction between the heliosphere and the local ISM.
