Puget Sound is partly reflecting the sun in this detailed image taken by astronauts on the International Space Station. Patterns of boat wakes are prominent in this reflection zone. The difference between the boat wakes in this view relates to the speed of the boat and the particular patterns (of several) that happen to be captured in the specific light reflection angles at the time the image was taken.
The land areas show parts of Seattle. The darkest areas with rectangular grids are suburbs richly covered with trees. The broadly gray zones of the central city are brighter where structures are lower, as in the harbor zone (Harbor Island), and darker where the shadows of high-rise buildings downtown cast black shadows. Interstate Highway 5 bisects downtown.