  We show that the electron thermal conductivity may strongly affect the
heliosheath plasma flow and the global pattern of the solar wind (SW)
interaction with the local interstellar medium (LISM). In particular, it leads
to strong reduction of the inner heliosheath thickness that makes possible to
explain (qualitatively) why Voyager 1 (V1) has crossed the heliopause at
unexpectedly small heliocentric distance of 122 AU. To estimate the effect of
thermal conductivity we consider a limiting case when thermal conduction is
very effective. To do that we assume the plasma flow in the entire heliosphere
is nearly isothermal.
  Due to this effect, the heliospheric distance of the termination shock has
increased by about 15 AU in V1 direction compared to the adiabatic case with
gamma = 5/3. The heliospheric distance of the heliopause has decreased by about
27 AU. As a result, the thickness of the inner heliosheath in the model has
decreased by about 42 AU and become equal to 32 AU.
