In this handout image provided by the European Space Agency (ESA) and NASA, the International Space Station and the docked space shuttle Endeavour orbit Earth during Endeavour's final sortie on May 23, 2011 in Space. Italian astronaut Paolo Nespoli captured the first-ever images of an orbiter docked to the International Space Station from the viewpoint of a departing vessel as he returned to Earth in a Soyuz capsule. (Photo by Paolo Nespoli - ESA/NASA via Getty Images)

An old toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. The exhibition focuses on how the toilet has changed our daily lives and discovers what the most environment-friendly and ideal toilet is. (Photo by Keith Tsuji/Getty Images)

These are the dunes of the Namib Desert, taken by Korea's Kompstat-2 satellite. The blue and white area is the dried riverbed of the Tsauchab river. (Photo by The European Space Agency)

Tourists kissing front of Malaysia's landmark Petronas Twin Towers with lights on before turned off to mark Earth Hour 2016 in Kuala Lumpur, Malaysia, 19 March 2016. Earth Hour takes place worldwide at 8.30 p.m. local time and is a global call to turn off lights for 60 minutes to raise awareness of the danger of global climatic change (Photo by Fazry Ismail/EPA)

A group of San Bushmen from the Khomani San community practice their hunter-gatherer craft in the Southern Kalahari desert on October 15, 2009 in the Kalahari, South Africa. One of the largest studies of African genetics by an international team from the University of Pennsylvania, published in April 2009, revealed that the San of Southern Africa are the most genetically diverse on earth, and that the San homeland could be the spot where modern humanity began. (Photo by Dan Kitwood/Getty Images)

Russian support personnel work to help get Expedition 29 crew members out of the Soyuz TMA-02M spacecraft shortly after the capsule landed with Expedition 29 Commander Mike Fossum, and Flight Engineers Sergei Volkov and Satoshi Furukawa on November 22, 2011 outside of the town of Arkalyk, Kazakhstan. NASA Astronaut Fossum, Russian Cosmonaut Volkov and JAXA (Japan Aerospace Exploration Agency) Astronaut Furukawa are returning from more than five months onboard the International Space Station (ISS) where they served as members of the Expedition 28 and 29 crews. (Photo by Bill Ingalls/NASA via Getty Images)

A woman cartwheels through the Coachella Valley Music and Arts Festival in Indio, California April 10, 2015. (Photo by Lucy Nicholson/Reuters)

A police officer removes a reveler from standing on a post as they guard and clear the street of revelers dressed in holiday themed costumes during SantaCon in New York Saturday, December 12, 2015. As thousands of Santa-suited merrymakers prepare to hit the city's streets and bars, organizers of the annual pub crawl say they're taking more steps than ever to deter naughty behavior. (Photo by Andres Kudacki/AP Photo)