Hubble Space Telescope Planetary Camera imaging of HH 29

We present Hubble Space Telescope Hex and [S II] images of HH 29. The proxi mity of HH 29 (140 pc) and the high resolution of the Planetary Camera has resulted in the most detailed images obtained so far of any Herbig-Haro obj ect. The most prominent feature is a linear Hat ridge leading the working s urface of a bow shock with a chaotic trailing [S II] bright region. The hig h-excitation ridge is perpendicular to a line extending toward the class 0 protostar L1551-NE, supporting its recent identification as the driving sou rce. Previous studies have identified several low-velocity features within the working surface. Our images reveal them to be miniature bow shocks faci ng upstream. Evidently a cluster of dense quasi-stationary clumps have been overrun by a faster, lower density flow. The shock front impacted the fron t of the largest clump several decades ago, and during the 1990s, a promine nt gap appeared in the advancing bow shock in the wake of the obstacle. The Hubble Space Telescope images show that by 1998 the shock front had wrappe d around the back of the clump, closing the shock shadow it produced.