Naomi Campbell attends the Swarovski Fashionation at Palazzo Reale on June 7, 2011 in Milan, Italy. (Photo by Vittorio Zunino Celotto/Getty Images)

Katy Perry attends the premiere of “The Smurfs” at the Ziegfeld Theater on July 24, 2011 in New York City. (Photo by Jemal Countess/Getty Images)

Models pose backstage ahead of the Review of Australian Fashion Week show as part of Mercedes Benz Fashion Festival Sydney 2011 at Sydney Town Hall on August 24, 2011 in Sydney, Australia. (Photo by Lisa Maree Williams/Getty Images)

A 12th century manuscript of The Old Testament sits in the Chained Library of Hereford Cathedral after it's annual spring clean on January 24, 2012 in Hereford, England. (Photo by Christopher Furlong/Getty Images)

Enthusiasts gather for the Model Rail Scotland exhibition on February 24, 2012 in Glasgow, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

Presenter Sofia Vergara arrives at the 88th Academy Awards in Hollywood, California February 28, 2016. (Photo by Adrees Latif/Reuters)

Steam emerges from a cooling tower of the nuclear power plant Leibstadt near Leibstadt, Switzerland, November 18, 2014. (Photo by Arnd Wiegmann/Reuters)

“Himalayan Dog”. This dog just appeared out of nowhere and followed us for an entire week during our trekking trip in the Himalayan outback. He always used to sleep in front of our tent and guarded us in the nights. When I decided to get up at 4 a.m. to climb the next 5000 m peak for sunrise he accompanied me as well. On the top he was sitting for the entire 30 minutes on this place looking straight into the countryside. Photo location: Ladakh, India. (Photo and caption by Sebastian Wahlhuetter/National Geographic Photo Contest)