This Sunday, September 7, 2014 photo provided by Rachel Kirk shows smoke from a fire rising above Little Yosemite Valley near Yosemite National Park, Calif. (Photo by Rachel Kirk/AP Photo)

Clouds gather as walkers pause atop a ridge in Mountain View, California January 7, 2016. (Photo by Noah Berger/Reuters)

Dancer Elizabeth Suarez, 29, gets ready to perform at the backstage of a cinema where the “Cuerda Viva” (Live Strings) alternative music festival is taking place, in Havana, February 26, 2016. (Photo by Alexandre Meneghini/Reuters)

Fog hangs between pine trees in a forest near Neubrueck, eastern Germany, on November 20, 2012. Meteorologists forecast cloudy sky and temperatures around 5 degrees Celsius for the region. (Photo by Patrick Pleul/AFP Photo)

Ellora is an archaeological site, 29 km (18 mi) North-West of the city of Aurangabad in the Indian state of Maharashtra built by the Rashtrakuta dynasty. It is also known as Elapura (in the Rashtrakuta literature-Kannada).

Talk-show host Oprah Winfrey interviewing cyclist Lance Armstrong during taping for the show "Oprah and Lance Armstrong: The Worldwide Exclusive" in Austin, Texas. The two-part episode of "Oprah's Next Chapter" will air nationally Thursday and Friday, Jan. 17-18, 2013. (AP Photo/Courtesy of Harpo Studios, Inc., George Burns)

From towering elephants to tiny insects, photographers will be offering a rare insight into the natural world at this year’s Wildscreen Photography Festival 2014. The festival, formerly known as WildPhotos, is the UK’s largest wildlife photography show. The Wildscreen Photography Festival 2014 will be taking place between 24-26 October at London’s Royal Geographical Society. (Photo by Sam Hobson/Wildscreen Photography Festival 2014)

On the western side of Mount Hood lies the longest glacier cave system in the contiguous United States. In 2012, these caves were mapped to a combined length of 7,166.8 feet by cave explorers Brent McGregor and Eddy Cartaya. Currently, the total passage length is hundreds of feet less. Glaciers are frozen rivers; they are always moving and changing... (Photo and caption by Josh Hydeman)