An astronaut on the International Space Station (ISS) shot this photograph of a portion of Padre Island, a long barrier island along the southern Texas coast. For this reason, the beach appears wider and extends farther seaward on South Padre Island. Stretching north from the channel, Padre Island National Seashore protects nearly 80 miles (130 kilometers) of beaches for nature and recreation. North and South Padre Islands are well known for attracting tourists and beachgoers, but they have also intrigued scientists. Extensive microbial mats—multi-layered sheets of microorganisms such as bacteria—take advantage of this natural protection and thrive in the protected tidal flats along the backshore of Padre Island.