Ingo Arndt / Burned trees in front of Grand Prismatic Spring, Midway Geyser Basin, Yellowstone National Park, Wyoming, USA, September 2011.

Ingo Arndt / Grand Prismatic Spring, Midway Geyser Basin, Yellowstone National Park, Wyoming, USA, September 2011.

Solvin Zankl / By-the-wind sailor (Velella velella) colony. Sargasso Sea, Bermuda.

Andy Rouse / Galapagos sea lion (Zalophus wollebaeki) silhouetted at sunset, Galapagos.

Peter Cairns / Twilight over Flakstad beach, Lofoten, Norway. February 2014.

Peter Cairns / Twilight over Flakstad beach, Lofoten, Norway. February 2014.

Ole Jorgen Liodden / Svalbard reindeer (Rangifer tarandus platyrhyncus) feeding at sunset, Spitsbergen, Svalbard, Norway, April.

Tom Gilks / Nyiragongo volcano lava lake, Virungas National Park, Democratic Republic of Congo February 2015.

Steven Kazlowski / Photographer in front of Northern lights / Aurora borealis glowing brightly over the frozen eastern Beaufort Sea, Arctic National Wildlife Refuge, Alaska Model released.

Alex Hyde / Alpine meadow, Nordtirol, Austrian Alps, July 2014.

Christophe Courteau / Light of the Creac'h Lighthouse at night. Ile d'Ouessant / Ushant, Finistere, Brittany, France, September 2011.

Wild Wonders of Europe / Bartocha / Early purple orchid (Orchis mascula) on the Forca Canapine, Monti Sibillini National Park, Italy, May.