Photographs by: CreditsCreditsCreditsKids snorkling: Poznyakov, Dreamstime; kid in forest: Lunamarina, Dreamstime; volcano tourists: Martinmark, Dreamstime; kids on glacier: Tomas Broucek, Dreamstime; cave: mangroove, Dreamstime; zip lining: Brad Sauter, Dreamstime; polar bear: Outdoorsman, Dreamstime; dolphin: Michael Price, Dreamstime; macaw: Yurakp, Dreamstime; gecko: Michiel De Wit, Dreamstime; tortoise: WCP Media, Dreamstime; red panda: Isselee, Dreamstime; snow cone: stuartbur, iStockphoto; red lollipop: Feng Yu, Dreamstime; vanilla ice cream: Ppy2010ha, Dreamstime; watermelon: Hyrman, Dreamstime; Key lime pie slice: Dlabajdesign, Shutterstock; mint ice cream: Michael Gray, Dreamstime; Brazil: Hans Magelssen, Dreamstime; South Africa: Andrea Willmore, Dreamstime; Russia: Dmitryminin, Dreamstime; Australia: Liverbird, Dreamstime; Thailand Rice Field sirichai_asawalapsakul, iStockphoto; Colombia: Sam Abell; surfing: Katerinasamsonova, Dreamstime; sand castles: Ievgeniia Arkhipova, Dreamstime; waves: Vadim Petrov, Dreamstime; seashells: Katarzyna Bialasiewicz, Dreamstime; tide pools: Foster Eubank, Dreamstime; reading: Jacek Chabraszewski, Dreamstime; planet illustrations by David A. Aguilar