The Sun's periods of rowdy activity may get all the glory , but even in its quieter times, our home star can subtly reshape its interior. According to a new analysis of decades' worth of data, the lulls in the Sun's 11-year activity cycle aren't identical – and measurable shifts in its internal vibrations occurred during the deepest solar minimum in recent history. "For the first time, we've been able to clearly quantify how the Sun's internal structure shifts from one cycle minimum to the next,