Visitors photograph an animatronic Tyrannosaurus Rex at the National Museum of Scotland, July 29, 2011. (Photo by David Moir/Reuters)

In this Thursday, May 8, 2014 photo, Iranian coal miners push metal carts to be loaded with coal at a mine near the city of Zirab 212 kilometers (132 miles) northeast of the capital Tehran, on a mountain in Mazandaran province, Iran. International sanctions linked to the decade-long dispute over Iran's nuclear program have hindered the import of heavy machinery and modern technology in all sectors, and coal mining is no exception. (Photo by Ebrahim Noroozi/AP Photo)

NASA says it could be another 20 years before humans touch down on Mars, but in a sense, the Mars Society has been exploring the red planet for more than a decade – in Utah. Photo: Csilla Orgel, a geologist of Crew 125 EuroMoonMars B mission, makes her way back to the Mars Desert Research Station (MDRS) in the Utah desert March 3, 2013. The MDRS aims to investigate the feasibility of a human exploration of Mars and uses the Utah desert's Mars-like terrain to simulate working conditions on the red planet. Scientists, students and enthusiasts work together developing field tactics and studying the terrain. All outdoor exploration is done wearing simulated spacesuits and carrying air supply packs and crews live together in a small communication base with limited amounts of electricity, food, oxygen and water. Everything needed to survive must be produced, fixed and replaced on site. (Photo by Jim Urquhart/Reuters)

The Lumix GX1 single lens reflex (SLR) camera with 14-42 mm powerzoom lens is displayed at the Panasonic booth at the 2012 International Consumer Electronics Show at the Las Vegas Convention Center January 10, 2012 in Las Vegas, Nevada. The new camera comes with an external viewfinder and flash and an ISO up to 12,800. The camera as shown sells for USD 949; the camera body alone is USD 799. (Photo by Ethan Miller/Getty Images)

Supporter Mette Peluce, 11, waits for U.S. Democratic presidential candidate Bernie Sanders to speak in East Los Angeles, California, U.S. May 23, 2016. (Photo by Lucy Nicholson/Reuters)

An Indonesian boy waits as he prepares to catch offerings released by Hindu devotees of the Tengger tribe during the Yadnya Kasada festival, on the crater of Mount Bromo in Probolinggo on July 21, 2016. During the annual Yadnya Kasada festival the Tenggerese climb Mount Bromo, an active volcano, and seek the blessing from the main deity Hyang Widi Wasa by presenting offerings of rice, fruit, livestock and other local produce. (Photo by Juni Kriswanto/AFP Photo)

A dramatic rise in owning exotic pets in China is fuelling global demand for threatened species. The growing trade in alligators, snakes, monkeys, crocodiles and spiders is directly linked to species loss in some of the world’s most threatened ecosystems. Here: A fennec fox (Vulpes zerda) is groomed in a pet store in central Beijing. Native to the Sahara in North Africa, the species became a popular pet after being depicted as a character in Disney’s 2016 animated movie Zootopia. Individuals can cost between $2,000–$3,000. (Photo by Sean Gallagher/The Guardian)