This image shows the site of impact G, comet Shoemaker-Levy 9, at 04:56 universal time (UT) (21:56 PDT) on July 19, 1994.
Impact G was the largest and most dramatic to date. At a wavelength of 550 nm, the impact point shows a dark core (approx 1.7 arc-sec in the narrow dimension) surrounded by a ring-like feature (approx 4 arc-sec in diameter). The dark core shows distinct sub-structure, and the ring is brighter on one side than on the other.
In this image, the south pole is up and east is to the left, so that the planet is rotating from left to right.
The imaging parameters were: Wavelength: 550 nm Bandwidth: 40 nm Plate scale: 0.063 arc-sec/pixel Size: 750 x 750 pixels (approx 47 arc-sec x 47 arc-sec)The image was reconstructed from 40 individual short-exposure speckle frames (exposure times of 200 ms and 300 ms, respectively) via a bispectral speckle imaging algorithm.
Observers: Claire Max, Don Gavel, Erik Johansson, LLNL Mike Liu, UC Berkeley Bill Bradford, UC Santa Cruz