04-19Large school of Munk's devil rays seen from the air, Gulf of California, Mexico - Mark Carwardine
04-18Montalbano Elicona, Messina, Sicily, Italy - Antonino Bartuccio/SOPA Collection/Offset by Shutterstock)
04-17New River Gorge Bridge in the New River Gorge National Park and Preserve, West Virginia - Entropy Workshop/iStock/Getty Images Plus)
04-15Jackie Robinson signs autographs at spring training in Ciudad Trujillo, now Santo Domingo, Dominican Republic, on March 6, 1948 - Bettmann/Getty Images)
04-12Earth viewed from the International Space Station, photographed by astronaut Jeff Williams - Jeff Williams/NASA)