A tourist walks inside the Ice Palace glacier hollow at Hintertux glacier, located at around 3250 meters above sea level, in Zillertal, Austria, 02 March, 2016. The hollow's temperature remains constant at 0 degrees Celsius, in summer and winter alike, and is also used by the University of Innsbruck for scientific research projects. (Photo by Lisi Niesner/EPA)

Emilia Pechinkova, a 24-years-old Bulgarian Pomak (Bulgarian speaking Muslims) bride poses for a photograph following the “gelina” or face painting ceremony carried out by female guests and relatives in preparation for her three-day wedding ceremony in the village of Draginovo, 100 kms southeast of Sofia on April 22, 2016. Bulgaria's Muslim population is one of the highest in the European Union. During the Communist regime religious rituals were not tolerated, and Muslims were forced to abandon wearing their traditional wedding outfits. Recently, more young Pomak women want to include traditional wedding customs that were forbidden during the regime, regardless of their secular lifestyles and the high cost of such a wedding. (Photo by Nikolay Doychinov/AFP Photo)

Children of Indian laborers play on make-shift swings in Amritsar, India, May 12, 2015. (Photo by Narinder Nanu/AFP Photo)

A photo made avialable on 05 August 2015 shows an Indian woman collecting drinking water from a water pump in the submerged village of Sreerampur, some 150 kilometers north of Calcutta, India, on 04 August 2015. At least 215 people have died in floods and a landslide following monsoon rains in India over the past week, 83 deaths were reported from the western state of Gujarat and 69 from eastern West Bengal. The worst-affected states were West Bengal, Gujarat and Rajasthan, the Home Ministry said. (Photo by Piyal Adhikary/EPA)

Indian commuters wade through floodwaters during the continuous rain shower in Calcutta, India, July 10, 2015. A monsoon shower hit the city and disrupted daily life. The Indian monsoon, takes place between May and September. (Photo by Piyal Adhikary/EPA)

A villager pours pesticide from a bucket as Mount Sinabung spews ash at Kebayaken village in Karo district, Indonesia's North Sumatra province, on December 4, 2013. The country has ordered the evacuation of 15,000 residents near the active volcano. (Photo by Roni Bintang/Reuters)

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)

Smithfield meat porters march on the Home Office, bearing a petition which calls for an end to all immigration into Britain, 25th August 1972. (Photo by Keystone/Hulton Archive/Getty Images)