The journey of the Sun through space carries the solar system through a
dynamic interstellar environment that is presently characterized by Mach 1
motion between the heliosphere and the surrounding interstellar medium (ISM).
The interaction between the heliosphere and ISM is an evolving process due to
the variable solar wind and to interstellar turbulence. Frisch et al. presented
a meta-analysis of the historical data on the interstellar wind flowing through
the heliosphere and concluded that temporal changes in the ecliptic longitude
of the wind were statistically indicated by the data available in the refereed
literature at the time of that writing. Lallement and Bertaux disagree with
this result, and suggested, for instance, that a key instrumental response
function of IBEX-Lo was incorrect and that the STEREO pickup ion data are
unsuitable for diagnosing the flow of interstellar neutrals through the
heliosphere. Here we show that temporal variations in the interstellar wind
through the heliosphere are consistent with our knowledge of local ISM. The
statistical analysis of the historical helium wind data is revisited, and a
recent correction of a typographical error in the literature is incorporated
into the new fits. With this correction, and including no newer IBEX results,
these combined data still indicate that a change in the longitude of the
interstellar neutral wind over the past forty years is statistically likely,
but that a constant flow longitude is now also statistically possible. It is
shown that the IBEX instrumental response function is known, and that the
STEREO pickup ion data have been correctly utilized in this analysis.
