1, Kzenon/Shutterstock 8, Fresh_water/Fotolia 17, Rivision/Fotolia 18, PeteMarovich/ZUMA Press/Alamy 19, Leo Mason/Alamy Live News 26, JTB Media Creation, Inc./Alamy 31, Edelweiss/Fotolia 38 (top), Ruben Sprich/Reuters 38 (middle), Olesya Shelomova/Fotolia 42, Rob/Fotolia 45, epa european pressphoto agency b.v./Alamy 46 (left), Deyan Georgiev/Fotolia 46 (right), Catmando/Fotolia 47, Glow Images 66, Jeff Greenberg 3 of 6/Alamy 67, Ian G. Dagnall/Alamy 70, Braden Gunem/ Alamy 71, Stuart Monk/Fotolia 75, Donvictorio/Shutterstock 77 (bottom left), Bepsphoto/Fotolia 77 (top right), Moreno Soppelsa/Shutterstock 77 (bottom right), Kzenon/Shutterstock 82, Jhk2303/Fotolia 83, Spaceport9/Fotolia 93, Andres Rodriguez/Fotolia

97, Blend Images/Glow Images 107, Taina Sohlman/Fotolia 108, Gladskikh Tatiana/Shutterstock 118, Pkstock/Fotolia 124, Africa Studio/Fotolia 125, Blend Images/Glow Images 127 (left), WavebreakMediaMicro/Fotolia 127 (top middle), Sor Jong Ang/Fotolia 127 (bottom middle), Velirina/Fotolia 127 (right), Charlie Harding/Robert Harding 133, Chor Sokunthea/Reuters 137 (top left), Pob_anythink/Fotolia 137 (bottom left), Bonzodog/Fotolia 137 (middle), Donvanstaden/Fotolia 137 (top right), Gabriele Maltinti/Fotolia 137 (bottom right), CnOra/Fotolia 148, Ekina/Fotolia 150, Eléonore H/Fotolia 152, Kalichka/Fotolia 153 (top left), Mark Lennihan/AP Photo 153 (bottom left), Kristoffer Tripplaar/Alamy 153 (right), Peter Mooji/Shutterstock

167, Wilfredo Lee/Associated Press 183 (top), Shanghai Daily/ Imaginechina/Associated Press 183 (bottom), Christian Delbert/Fotolia 187, Wilfredo Lee/Associated Press 188 (top), SeanPavonePhoto/Fotolia 188 (bottom), Riccardo Valsecchi/Demotix/Corbis 197, Qushe/Shutterstock 210, Dario Sabljak/Fotolia

225, 236, Warren Goldswain/Shutterstock 237 (left), Selezenj/Fotolia 237 (right), Sakhorn/Shutterstock 279, Monika Wisniewska/Fotolia 294, TATSIANAMA/Shutterstock

311, Igor Mojzes/Fotolia 321, David Madison/Digital Vision/Getty Images 322, Yanik Chauvin/Fotolia 331 (left), Viappy/Fotolia 331 (right), Kolett/Fotolia 332 (top left), Gladskikh Tatiana/Shutterstock 332 (bottom left), Igor Mojzes/Fotolia 332 (right), NetPhotos/Alamy 333, Blend Images/Glow Images 343, US Air Force Photo/Alamy 346, HUAJI/ Shutterstock 347, Stephen Rees/Shutterstock 372, Wiktor Bubniak/Fotolia 375, BibleLandPictures/Alamy 376, Andrey_Popov/Shutterstock 377 (left), Steve Healey 377 (right), Nyiragongo/Fotolia 378 (left), Petoo/Fotolia 378 (top right), Jonathan Little/Alamy 378 (bottom right), Cozyta/Fotolia 379 (left), Associated Press 379 (right), Rjack/Fotolia

393, Eric Nathan/Robert Harding 399, Bigfoot/Fotolia 401, Spiderstock/Shutterstock 404, Michael Nichols/National Geographic/Getty Images 407, SurangaSL/Sh/Shutterstock 409, Marjorie McBride/Alamy 410, Liunian/Shutterstock 411, Mrakhr/Fotolia 412, Aerial Archives/Alamy 414 (left), Icy Straight Point 414 (right), Eric Nathan/Robert Harding 416, Hemis/Alamy 430, Roza/Fotolia 431, Yaacov Dagan/Alamy 440, © 2006 The Children’s Museum of Indianapolis 441, Antonio Gravante/Fotolia 446 (left), Courtesy of Goss Graphics Systems 446 (right), epa European pressphoto agency b.v./Alamy 472, Polder/Shutterstock 478, ChrisVanLennepPhoto/Fotolia 489, Marcuspon/Fotolia

493, Henryk Sadura/Fotolia 506, Ikonoklast Fotografie/Shutterstock 514, Oceanfishing/Shutterstock 543 (left), Henryk Sadura/ Fotolia 543 (right), Amy Walters/Shutterstock 544, NASA

555, Caro/Alamy 560, Andre Jenny/Alamy 565, Oloololo/Fotolia 566, Graphlight/Fotolia 571, moodboard/Alamy 575 (left), Caro/Alamy 575 (top right), Randy Faris/Corbis 575 (bottom right), William O’Brien, Jr., LLC 631, Jill Giardino/Glow Images

635, epa European pressphoto agency b.v./Alamy 648 (left), Monkey Business Images/Shutterstock 648 (right), SOMATUSCANI/Fotolia 649, Alarsonphoto/ Fotolia 650, Adrian Sherratt/Alamy 657 (top left), epa european pressphoto agency b.v./Alamy 657 (bottom left), Stockyimages/Fotolia 657 (right), Don Emmert/AFP/Getty Images/Newscom 666, Dennis MacDonald/Alamy 670, Richard Cummins/SuperStock 674, GWImages/Shutterstock 675, Aleph Studio/Shutterstock 683, Lijuan Guo/Shutterstock 698, Aastock/Shutterstock 701, Sima/Fotolia 702, Furmananna/Fotolia

719, Wiskerke/Alamy 734, Jason Tench/Shutterstock 736, Wiskerke/Alamy 744, Frank Oppermann/Shutterstock 756 (left), Pavel Losevsky/Shutterstock 756 (top right), Stefan Wackerhagen/Glow Images 756 (bottom right), DenisNata/Fotolia

791, Jeff Lewis/Icon SMI 910/Jeff Lewis/Icon SMI/Newscom 798, Carola Schubbel/Fotolia 805, epitavi/Shutterstock 806, Greg Ashman/Icon SMI CCJ/Greg Ashman/Icon SMI/Newscom 812, Jeff Lewis/Icon SMI 910/Jeff Lewis/Icon SMI/Newscom 833, ZUMA Press, Inc./Alamy 845, Abaca Press/KRT/Newscom 851, Vojtech Vlk/Fotolia 857, David Coleman/Alamy