An artist's impression of a growing supermassive black hole located in the early Universe is seen in this NASA handout illustration released on June 15, 2011. Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA's Chandra X-Ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies. (Photo by Reuters/NASA/Chandra X-Ray Observatory/A.Hobart)

Members of the “Avalon” team wearing 14th century knight costumes fight against each other on the bank of the Yenisei River during the regional amateurs tournament of clubs of historical reconstruction, “The Battle of the Nations 2015. Siberia”, in Krasnoyarsk January 24, 2015. (Photo by Ilya Naymushin/Reuters)

“Kids of Sapa”. Four little beautiful Hmong girls from Lao Chai Village, near Sapa, Vietnam. (Photo and caption by Felipe Hanower/National Geographic Traveler Photo Contest)

These stunning pictures show a normally vicious tiger calmly swimming in a pool of algae, on Jule 9, 2014. The powerful cat takes a refreshing break by taking a dip in the bright green algae. But it looks like this big cat is scared of getting his head wet as he strains to keep it above the water. After splashing around for a bit the tiger gets out and tries to air-dry with specks of the vegetation dripping off his fur. The striking pictures were taken at Copenhagen zoo by snapper Soren Lundgren Neilson. (Photo by Soren Nielsen/Caters News)

Soma-Nomaoi is a festival that recreates a battle scene from more than 1,000 years ago. It is annually held for 4 days from July 22 to 25 in Haramachi City, Fukushima Prefecture, in the eastern part of Japan. In this historical event, 600 mounted samurai in traditional Japanese armor, with long swords at their side and ancestral flagstaffs streaming from their backs, ride across open fields. Soma-Nomaoi has been designated an Important Intangible Folk Cultural Property.

Photo: A young woman (C) clad in samurai costume leads other local poeple as she rides her horse during a parade at the annual Soma Nomaoi festival in Minamisoma, Fukushima Prefecture, on July 28, 2012. The traditional full-scale festival kicked off for the first time after the accident of the Fukushima Dai-ichi Nuclear Power Plant following the massive earthquake and the tsunami on March 11, 2011. (Photo by Toru Yamanaka/AFP Photo)

Dog puppy “Sandy” protects against the rain with an umbrella fixed on her leash during a stroll in Rust, southern Germany, on May 26, 2013. (Photo by Patrick Seeger/AFP Photo)

A timber truck driver (L) dressed as Father Frost is saluted by a soldier at the Kremlin's Spasskiye (Saviour) Gate in Moscow, Russian Federation, on December 24, 2013. (Photo by Vyacheslav Prokofyev/ITAR-TASS/ZUMA Press)

Members of the Wasteland Warriors from the movie “MadMax” pose during the Wacken Open Air festival on August 4, 2016 in Wacken, Germany. Wacken is a village in northern Germany with a population of 1,800 that has hosted the annual festival, which attracts heavy metal fans from around the world, since 1990. (Photo by Alexander Koerner/Getty Images)