  On its journey through the Galaxy, the Sun passes through diverse regions of
the interstellar medium. High-resolution spectroscopic measurements of
interstellar absorption lines in spectra of nearby stars show absorption
components from more than a dozen warm partially ionized clouds within 15 pc of
the Sun. The two nearest clouds - the Local Interstellar Cloud (LIC) and
Galactic (G) cloud - move toward each other. Their bulk heliocentric velocities
can be compared with the interstellar neutral helium flow velocity obtained
from space-based experiments. We combine recent results from Ulysses, IBEX, and
STEREO observations to find a more accurate estimate of the velocity and
temperature of the very local interstellar medium. We find that, contrary to
the widespread viewpoint that the Sun resides inside the LIC, the locally
observed velocity of the interstellar neutral helium is consistent with a
linear combination of the velocities of the LIC and G cloud, but not with
either of these two velocities. This finding shows that the Sun travels through
a mixed-cloud interstellar medium composed of material from both these clouds.
Interactions between these clouds explain the substantially higher density of
the interstellar hydrogen near the Sun and toward stars located within the
interaction region of these two clouds. The observed asymmetry of the
interstellar helium distribution function also supports this interaction. The
structure and equilibrium in this region require further studies using in situ
and telescopic observations.
