Farol Beach, Farol Cay, Rocas Atoll, Rio Grande do Norte, Brazil

   The only atoll in the South Atlantic, Rocas Atoll lies 144 miles off Brazil’s eastern shore. The Atol das Rocas Biological Reserve is designated as a Brazilian wildlife refuge and UNESCO World Heritage Site. The atoll and surrounding waters are reserved for scientific research. The atoll provides habitats for migratory seabirds, nesting turtles and other organisms.


   Farol Cay is built of reef rubble as reflected in this sand. Many grains, including the kidney-shaped disc near the edge at 3 o’clock are fragments of coralline algae, chiefly Halimeda. Small circular forams are scattered through the sample (some white, some stained orange). Minute snails include the orange shell at 6 o’clock, a tan one on the edge at 7 o’clock and a white one at 1 o’clock. On the right edge, a round pink shell sits next to a small curved cylinder, Caecum, a micromollusc. The black and gray triangle in the center and brown triangle at 4 o’clock are tips from crab claws.

Image Science and Analysis Laboratory, NASA-Johnson Space Center. 01/13/2012 21:55:14. [Public domain]