American surfer Garrett "GMAC" McNamara rides what could be, if confirmed, the biggest wave conquered in history as a crowd watches Monday in Nazare, Portugal. To Mane/Barcroft Media /Landov hide caption

itoggle caption To Mane/Barcroft Media /Landov

Twins in Malawi helped scientists discover a role the gut microbiome appears to play in severe malnutrition. Photograph courtesy of Tanya Yatsunenko hide caption

itoggle caption Photograph courtesy of Tanya Yatsunenko

International ships call at the busy Port of New Orleans. It's a major shipping convergence point on the Mississippi River. Ships come upriver from the Gulf of Mexico with imports from abroad, and barges come downriver, bringing U.S. goods for export. Debbie Elliott/NPR hide caption

itoggle caption Debbie Elliott/NPR

Highly detailed sonar systems aboard the research vessel Pritchard gave researchers a clear view of the sediment on the seafloor off Long Island. Courtesy of John Goff/University Of Texas hide caption

itoggle caption Courtesy of John Goff/University Of Texas

Out For Lunch? Researchers estimate that billions of birds and small mammals are killed by cats in the U.S. annually. Vishnevskiy Vasiliy/iStockphoto hide caption

itoggle caption Vishnevskiy Vasiliy/iStockphoto

The eye of Hurricane Earl in the Atlantic Ocean, seen from a NASA research aircraft on Aug. 30, 2010. This flight through the eyewall caught Earl just as it was intensifying from a Category 2 to a Category 4 hurricane. Researchers collected air samples on this flight from about 30,000 feet over both land and sea and close to 100 different species of bacteria. Jane Peterson/NASA hide caption

itoggle caption Jane Peterson/NASA

Cows graze in front of the Rosengarten mountain massif in northern Italy. Pasture grazing is practiced throughout the Alps. Matthias Schrader/Associated Press hide caption

itoggle caption Matthias Schrader/Associated Press