A performer dances at a housing exhibition in Wuhan, Hubei province, China, September 27, 2015. (Photo by Reuters/Stringer)

Tribal artists and supporters from the southern Indian state of Karnataka dance outside the residence of Congress Party President Sonia Gandhi during her birthday celebrations in New Delhi, India, Wednesday, December 9, 2015. The Italian-born Gandhi is the widow of former Prime Minister Rajiv Gandhi and has led the Congress party since 1998. (Photo by Altaf Qadri/AP Photo)

Humboldt Penguins swim in their pool as a keeper looks on through a spherical window during the annual stocktake press preview at London Zoo in Regents Park in London Monday, January 4, 2016. A requirement of ZSL London Zoo's license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where it's used to manage the worldwide breeding programmes for endangered animals. (Photo by Alastair Grant/AP Photo)

Seven year old Hungarian herding dog Derci runs along the Olympiaberg hill during stormy weather in Munich, southern Germany, Monday, January 4, 2016. (Photo by Matthias Balk/DPA via AP Photo)

Israeli soldiers play the parts of wounded civilians during a drill simulating a toxic spill from an attack on a train in Beersheba, southern Israel, 13 January 2016, as Home Front medical teams, fire fighters and police carry out rescue operations. The large scale drill is the concluding exercise of the Fourth International Conference on Healthcare System Preparedness and Response to Emergencies and Disasters and includes some 200 of the world's experts on health system readiness from around the world. The conference is dealing with all types of medical emergencies from terrorist attacks to natural disasters. (Photo by Jim Hollander/EPA)

Veteran racehorse Morestead models the world's first authentic Harris Tweed suit designed for a racing horse, which has been specially commissioned by William Hill to celebrate the opening of this year's Cheltenham Festival on March 15, 2016 in the U.K. (Photo by Joe Pepler/Rex Features/Shutterstock)

Lowry Park Zoo elephants Matjeka, 23, and her 1-year-old daughter, Mavi, apply a liberal coating of “sunscreen” to themselves in a clay mud wallow at the park Tuesday, August 12, 2014, in Tampa, Fla., on the park's first observation of World Elephant Day to raise awareness of the wild African elephant crisis. “Elephants are prone to being sunburned”, said associate curator Chris Massaro. “What they need is lot of mud or clay to roll around in and cover up their skin so it will protect it from the sun”. (Photo by Cherie Diez/AP Photo/The Tampa Bay Times)

This image made available by the Johns Hopkins University Applied Physics Laboratory on Wednesday, May 31, 2017 depicts NASA's Solar Probe Plus spacecraft approaching the sun. On Wednesday, NASA announced it will launch the probe in summer 2018 to explore the solar atmosphere. It will be subjected to brutal heat and radiation like no other man-made structure before. (Photo by Johns Hopkins University Applied Physics Laboratory via AP Photo)