  We present the serendipitous discovery of 195 extragalactic globular clusters
(GCs) in one of the deepest optical images ever obtained, a 126 orbit HST/ACS
imaging study of the nearby Galactic GC NGC 6397. The distant GCs are all found
surrounding a bright elliptical galaxy in the field, and are among the faintest
objects detected in the image, with magnitudes 26 < F814W < 30. We measure the
redshift of the parent elliptical galaxy, using GMOS on Gemini South, to be z =
0.089 (375 Mpc). This galaxy, and its associated clusters, therefore ranks as
one of the most distant such systems discovered to date. The measured light
from these clusters was emitted 1.2 Gyr ago (the lookback time) and therefore
the optical properties hold clues for understanding the evolution of GCs over
the past Gyr. We measure the color function of the bright GCs and find that
both a blue and red population exist, and that the colors of each
sub-population are redder than GCs in local elliptical galaxies of comparable
luminosity. For the blue clusters, the observed color difference from z = 0.089
to today is only slightly larger than predictions from stellar evolution (e.g.,
changes in the luminosity and color of the main-sequence turnoff and the
morphology of the horizontal branch). A larger color difference is found in the
red clusters, possibly suggesting that they are very metal-rich and/or
significantly younger than 12 Gyr.
