Popular Mobilization Forces (PMF) fires towards Islamic State militants during a battle with Islamic State militants, west of Mosul, Iraq February 22, 2017. (Photo by Reuters/Stringer)

Paramasivan points to the statue of sun god Surya at a temple outside the Kodaikanal Solar Observatory, India, February 5, 2017. In the early morning darkness, Devendran P. walks up a hill to a solar observatory in India's southern hill town of Kodaikanal, trudging the same path his father and grandfather walked in a century-old family tradition of studying the sun. (Photo by Danish Siddiqui/Reuters)

Miners work extremely long days under the hot sun and the hours are often longer in illegal mines in Ghana, West Africa, 2014. An Australian photographer has captured the harsh reality of illegal mining under the unforgiving sun with these Ghanaian miners. (Photo by Heidi Woodman/Barcroft Images)

Elena from Dresden has her hair ruffled by the wind as she stands on a visitors' platform on the Maintower in Frankfurt am Main, western Germany, during stormy weather on February 22, 2017. (Photo by Arne Dedert/AFP Photo/DPA)

Riot policemen launch tears gas canisters during clashes with coca growers from Yungas in La Paz, Bolivia February 21, 2017. (Photo by David Mercado/Reuters)

Pope Francis attends a circus performance during his weekly general audience at Paul VI hall on December 22, 2016 at the Vatican. (Photo by Alberto Pizzoli/AFP Photo)

Four pillars of light from the 4 Laser Guide Star Facility on ESO's Very Large Telescope (VLT) are shown reaching into the Chilean night sky in this image from ESO Photo Ambassador Fred Kamphues, on September 2, 2016. The lasers are a key part of the adaptive optics system on the VLT. Adaptive optics allows astronomers to drastically reduce the atmospheric distortion present at even the best sites in the world for astronomy, including Paranal in Chile, the home of the VLT. (Photo by F. Kamphues/ESO)

Retired Malam Jabba engineer Akbar Ali skis down the piste at the ski resort in Malam Jabba, Pakistan February 7, 2017. Atop the piste of Malam Jabba in Pakistan's once dangerous Swat Valley skiers schuss downhill, a new Chinese-built chairlift ferries tourists to the peak, and a luxury hotel is under construction to replace one torched by the Taliban. (Photo by Caren Firouz/Reuters)