  The Sun shrinks during solar maximum and regrows during solar minimum by a
few kilometers. Here, we observe, for the first time, that the solar radius
variation shows planetary relationship. This suggests that some remote
planetary links must exist, even though this is unexpected within known
physics. Therefore, we speculate about its cause, which is the driving idea
behind this investigation. Namely, it must be some generic as yet invisible
streaming matter from the dark Universe. The associated energy change is
massive although it extends from months to several years. The impact by the
tentative invisible massive matter accumulates with time, triggering slowly the
underlying processes. This study shows that the sun size response is as short
as a few months. Then, the solar system is the target and the antenna of still
unidentified external impact, assuming to be from the dark sector.
