Keck image: Mike Brown; Galileo image: NASA / JPL / Ted Stryk
Europa from the Keck telescope and the Galileo spacecraft
The brighter parts of the Keck image shows where there is less water ice. The Galileo image is of a slightly different face than the Keck image; the non-water ice spot that shows up so clearly in the Keck image is the paleish reddish yellowish terrain in the bottom left quadrant of the Galileo image. The composition of that material has been a mystery since the time of Voyager.