An air tanker drops fire retardant on flames as firefighters continue to battle against the Detwiler fire in Mariposa, California on July 19, 2017. The Detwiler fire is currently at 7 percent containment and has burned more than 45,000 acres and destroyed eight structures. (Photo by Josh Edelson/AFP Photo)

Members of the media film as a ranger performs a post mortem on the carcass of a rhino after it was killed for its horn by poachers at the Kruger national park in Mpumalanga province August 27, 2014. Rhino poachers in South Africa now risk giving themselves away when they shoot thanks to a high-tech, gunfire-detection system being piloted in the country's flagship Kruger National Park. The stakes are high, for rhinos are being slain in escalating numbers for their prized horns, alarming both conservationists and the government since wildlife in South Africa is an important tourist draw. (Photo by Siphiwe Sibeko/Reuters)

The northern lights, or aurora borealis, illuminate the sky over Flakstad beach on Lofoten Islands in the Arctic Circle on September 5, 2017. (Photo by Jonathan Nackstrand/AFP Photo)

A tower belonging to the Abengoa solar plant at the Solucar solar park is seen in Sanlucar la Mayor, Spain on October 1, 2018. (Photo by Marcelo del Pozo/Reuters)

“NASA's Mars rover Opportunity just celebrated its ninth anniversary on Mars – a mission that was originally meant to last just 90 days...” – The Atlantic. Photo: NASA's rover Opportunity visits Victoria Crater, viewed from orbit by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter in october of 2006. Opportunity is a small dot on the crater's lip, at top right. Opportunity first reached the crater's rim on September 27, 2006. (Photo by NASA/JPL-Caltech/University of Arizona via The Atlantic)

“The Last Pollen Spore Preparing to Leave a Ladybug Trying to Hold On, Because It Didn't Want to Be Alone”. Photo by Hiep Nguyen Hoang (Hanoi, Vietnam). Photographed in Hanoi, Vietnam, April 2012.

“Originally published in the April 9, 1951, issue of LIFE magazine, W. Eugene Smith’s photo essay, «Spanish Village», has been lauded for more than six decades as the most moving photographic portrait ever made of daily life in rural Spain during the rule of dictator Francisco Franco”. – Time & Life Pictures. Photo: His wife, daughter, granddaughter and friends have their last earthly visit with a villager. (Photo by W. Eugene Smith/Time & Life Pictures)

Frontier soldiers run as a storm surge hits the coastline under the influence of Typhoon Fitow in Wenling, Zhejiang province, October 6, 2013. China issued a red alert ahead of Typhoon Fitow, which is expected to lash east of the country on Sunday evening. (Photo by Reuters/China Daily)