  The definition of nearby star systems is incomplete without an understanding
of the dynamical interaction between the stars and ambient interstellar
material. The Sun itself has been immersed in the Local Bubble interior void
for millions of years, and entered the outflow of interstellar material from
the Scorpius-Centaurus Association within the past $\sim10^5$ years.
Heliosphere dimensions have been relatively large during this period. A subset
of nearby stars have similar recent histories, and astrosphere properties are
predictable providing ambient interstellar matter and stellar activity cycles
are understood. The properties of astrospheres can be used to probe the
interstellar medium, and in turn outer planets are more frequently immersed in
raw interstellar material than inner planets.
