Recording artist Lady Gaga performs during a stop of The Monster Ball Tour at the MGM Grand Garden Arena March 25, 2011 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)

The Breitling DC-3, HB-IRJ, plane fly escorted by Italian Air Force's aerobatic demonstration team, the Frecce Tricolori, during the last stage of its world tour two days ahead of the International Sion Air Show, in Sion, Switzerland, 13 September 2017. From March to September 2017, the Breitling DC-3 from 1940 has done a grand world tour in several stages, over 28 countries and flies 50000km, an amazing accomplishment for this legendary plane that will be celebrating its 77th birthday. (Photo by Christian Merz/EPA/EFE)

The new Batmobile designed by Gordon Murray to be used in the live stage production of Batman Live World Arena Tour is unveiled for the first time at LH2 Studios on June 15, 2011 in London, England. (Photo by Gareth Cattermole/Getty Images)

A Porcupine on display during the PBS portion of the 2010 Summer TCA Press Tour at the Beverly Hilton Hotel on August 5, 2010 in Beverly Hills, California. (Photo by Frederick M. Brown/Getty Images)

In this March 31, 2019 photo, an Egyptian student borrows a Bedouin wedding dress to pose for a photograph with Bedouin men from the Hamada tribe, in Wadi Sahw, Abu Zenima, in South Sinai, Egypt. Four Bedouin women are for the first time leading tours in Egypt’s Sinai Peninsula, breaking new ground in their deeply conservative community, where women almost never work outside the home or interact with outsiders. The tourists can only be women, and the tours can’t go overnight. Each day before the sun sets, the group returns to the Hamada’s home village in Wadi Sahu, a narrow desert valley. (Photo by Nariman El-Mofty/AP Photo)

British artist, Mark Coreth sits on top of the “Sydney Ice Bear” carved from a 10 tonne block of ice to illustrate how humans affect climate change in the Arctic at Customs House on June 3, 2011 in Sydney, Australia. The public will be welcomed to touch the bear, and leave an imprint which will begin the melting process and act as a metaphor for how humans affect the environment. The ice bear's has visited six cities on it's global tour since 2009; the visit to Sydney coincides with World Environment Day on June 5. (Photo by Lisa Maree Williams/Getty Images)

A humpback whale is seen at the beginning of whale watching season during a Manly Whale Watching tour on June 8, 2011 in Sydney, Australia. The first day of winter in New South Wales, June 1st, marks the start of the Humback and southern right whales migration from southern regions to the north to warmer waters. Whale watchers should expect tohave plenty to see with the whale population increasing each year. The migration north continues through July and with the whales returning between September and November. (Photo by Cameron Spencer/Getty Images)

The Vietnam Slide Project was created by photo editor Kendra Rennick, who began collecting photo slides after a close friend lost her father, a Vietnam veteran. Her friend found a box of slides that her father had taken while in Vietnam and from there Rennick has continued to collect photographs that Vietnam veterans took during their tours of duty. Here: A photo taken from the collection of D.Thornton, who served in the First Air Cavalry division of the United States Army. (Photo by D.Thornton/The Vietnam Slide Project)