A man photographs the main engines of the space shuttle orbiter Discovery on display at the Udvar-Hazy Smithsonian National Air and Space Annex Museum in Chantilly, Virginia August 28, 2015. Shuttle Discovery had 27 years of service and flew 39 times before being retired in 2011. (Photo by Gary Cameron/Reuters)

Recording artists Demi Lovato (L) and Iggy Azalea perform on the Pepsi Stage, during the 2015 MTV Video Music Awards, at The Orpheum Theatre on August 30, 2015 in Los Angeles, California. (Photo by Frederick M. Brown/Getty Images for MTV)

Tourists play in front of a 3D painting on the wall of a house in Luoyuan village, Jinhua, Zhejiang province, August 26, 2015. The village hired a team to put on 3D paintings all over the valley as a method to attract tourists and improve the income of local villagers, according to local media. (Photo by Reuters/China Daily)

U.S. players push head coach Adam Krikorian into the pool after they defeated the Netherlands in their women's water polo gold medal match during the Aquatics World Championships in Kazan, Russia, August 7, 2015. (Photo by Michael Dalder/Reuters)

Henry Leese drives a 1952 British Rail Ivatt number 46512 at Strathspey Steam Railway on August 27, 2013 in Aviemore,Scotland. This year marks the 150th anniversary of the Highland Main Line built as a transportation link to the South for lairds and landowners living in northern Scotland. (Photo by Jeff J. Mitchell)

Revellers ride during the 54th annual brass band festival in the Serbian village of Guca August 7, 2014. Every year Guca is swamped by thousands of people taking part in the celebration of brass band music. (Photo by Marko Djurica/Reuters)

Revelers of the Holi Festival of Colors dance after throwing colored powders in the air in Madrid, Spain, Saturday, August 9, 2014. The festival is fashioned after the Hindu spring festival Holi, which is mainly celebrated in the north and east areas of India. (Photo by Daniel Ochoa de Olza/AP Photo)

Newborn giant panda triplets, which were born to giant panda Juxiao (not pictured), are seen inside an incubator at the Chimelong Safari Park in Guangzhou, Guangdong province August 9, 2014. According to local media, this is the fourth set of giant panda triplets born with the help of artificial insemination procedures in China, and the birth is seen as a miracle due to the low reproduction rate of giant pandas. (Photo by Reuters/China Daily)