  Using the technique of PSF-matched image subtraction, we have analyzed
archival HST/WFPC2 data to reveal details of at least two light-echo
structures, including some unknown before now, around SN 1993J in the galaxy
M81. In particular, we see one partial sheet of material 81 pc in front of the
SN and tilted ~60 deg relative to the disk plane of M81, and another 220 pc in
front of the SN, roughly parallel to the disk. The inferred echoing material is
consistent with the HI surface density detected in this region of M81's disk;
however, these data imply a fragmented covering factor for the echoing
structures. We discuss prospects for future (roughly annual) visits by HST to
image these and yet undiscovered echoes in the interstellar and circumstellar
environment of SN 1993J.
