Breakwater, artificial offshore structure protecting a harbour, anchorage, or marina basin from water waves. Breakwaters intercept longshore currents and tend to prevent beach erosion.
photosphere. luminous, apparently opaque layer of gases that forms the visible surface of the sun sun,intensely hot, self-luminous body of gases at the center of the solar system.
Best Answer: The sun has a visible disk called the photosphere, which is always present. The outer portions of that disk appear slightly darker than the middle of the disk. That is known as limb darkening and it is also always present.