The space shuttle Endeavour is transported to the California Science Center in Exposition Park from Los Angeles International Airport (LAX) in Los Angeles, California. (Photo by Kevork Djansezian)

A biker passes by a pair of mailboxes in the Capitol Hill neighborhood November 6, 2012 in Denver, Colorado. Colorado is considered by most experts to be one of the key battleground state in this year's presidential election. (Photo by Marc Piscotty/AFP Photo)

An archer in a samurai warrior costume aims at a target in the Asakusa Yabusame horseback archery event at Sumida Park in Tokyo, Saturday, April 18, 2015. (Photo by Shizuo Kambayashi/AP Photo)

A boy carries a dog as he stands after a Peruvian police operation to destroy illegal gold mining camps in a zone known as Mega 14, in the southern Amazon region of Madre de Dios July 14, 2015. Peruvian police razed dozens of illegal gold mining camps at the edge of an Amazonian nature reserve this week, part of a renewed bid to halt the spread of wildcatting in a remote rainforest region. (Photo by Janine Costa/Reuters)

A picture made available on 17 July 2015 shows the bright line of the Milky Way above the old oaks at the Rogalin landscape Park in Rogalin village, near Poznan, on the night of 16 July 2015. (Photo by Lukasz Ogrodowczyk/EPA)

Young Buddhist novice monks play at a Tibetan nomadic summer grazing area on July 24, 2015 on the Tibetan Plateau in Yushu County, Qinghai, China. Tibetan nomads face many challenges to their traditional way of life including political pressures, forced resettlement by China's government, climate change and rapid modernization. The Tibetan Plateau, often called “The Roof of the World”, is the world's highest and largest plateau. (Photo by Kevin Frayer/Getty Images)

People line up to pay inside a Makro supermarket in Caracas, January 9, 2015. Venezuela's socialist government decreed an “economic emergency” on Friday that will expand its powers and published the first data in a year that shows the depth of a recession fueled by low oil prices and a sputtering state-led model. (Photo by Jorge Silva/Reuters)

Tattoo artists work on clients during the second International Tattoo Festival in Sochi, Russia, April 23, 2016. (Photo by Kazbek Basayev/Reuters)