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)

Photographer and animal lover Chris Keeney shows how to use a PetCam with your own pet and offers expert technical know-how and inspiring creative suggestions to get you started. This is Coulee, a border collie/golden retriver mix from Lethbridge, Alberta, Canada. (Photo by Chris Keeney/Princeton Architectural Press)

Pedestrians stop to look at and photograph a DeLorean Motor Company DMC-12 customized to look identical to the car used in the film "Back to the Future Part II" and that will be part of a Lyft promotion in New York, October 21, 2015. In the 1989 movie, main character Marty McFly traveled to the future to October 21, 2015. (Photo by Lucas Jackson/Reuters)

An Iraqi Shi'ite boy poses for a photograph as Iraq Shi'ite Muslims commemorate Ashura in Baghdad, October 24, 2015. Ashura, which falls on the 10th day of the Islamic month of Muharram, commemorates the death of Imam Hussein, grandson of Prophet Mohammad, who was killed in the seventh century battle of Kerbala. (Photo by Ahmed Saad/Reuters)

Drastic inequality is by no means new in New York. Jacob A. Riis was called a muckraker after he chose to spotlight the city’s poverty at the turn of the 20th century by photographing it. Here: Sweatshop in Hester Street, 1889-1890. (Photo by Jacob A. Riis/Museum of the City of New York, Gift of Roger William Riis)

A Filipino transgender woman holds a huge red ribbon symbolizing fight against the HIV virus as she poses before photographers, during a World Aids Day celebration in Manila, Philippines, December 1, 2015. (Photo by Erik De Castro/Reuters)

These images of an abandoned theater act as a time capsule of a location that was once rocked by the stars. The likes of Metallica, R.E.M. and Motorhead all played the Variety Theatre in Cleveland, Ohio, but now all that remains are dusty chairs that once supported encapsulated crowds. Renowned abandoned building photographer Matthew Christopher photographed the theater in its dilapidated state. Here: The Variety Theatre, Cleveland, Ohio. (Photo by Matthew Christopher/Caters News)

A photograph made available on 30 September 2016 showing wind turbines at the site of the highest wind park in Europe at the Griessee, near the Nufenenpass in the Swiss south Alpes, Valais, Switzerland, on 23 September 2016. The four wind turbines of this wind park were developed by the company SwissWinds GmbH and are inaugurated on, 30 September 2016. (Photo by Olivier Maire/EPA)