  Evolved mass-losing stars such as Mira enrich the interstellar medium (ISM)
significantly by their dust-rich molecular wind. When these stars move fast
enough relative to the ISM, the interaction between the wind and ISM generates
the structure known as the astropause (a stellar analog of the heliopause),
which is a cometary stellar wind cavity bounded by the contact discontinuity
surface between the wind and ISM. Far-infrared observations of Mira spatially
resolve the structure of its astropause for the first time, distinguishing the
contact surface between Mira's wind and the ISM and the termination shock due
to Mira's wind colliding with the ISM. The physical size of the astropause and
the estimated speed of the termination shock suggest the age of the astropause
to be about 40,000 yr, confirming a theoretical prediction of the shock
re-establishment time after Mira has entered the Local Bubble.
