An artist shows her hands after working on a wall as part of a campaign to call for coexistence and the renouncement of violence through the painting of walls in Sanaa, Yemen March 15, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

ESA astronaut Paolo Nespoli looks on after landing back on Earth from their Soyuz TMA-20 spacecraft on May 24, 2011 in Zhezkazgan, Kazakhstan. The mission of the Soyuz TMA-20 was launched last December to the International Space Station with the flight engineers Catherine Coleman from the United States, Russian cosmonaut Dmitry Kondratyev and Italian astronaut Paolo Nespoli. The next expedition is expected to launch this June. (Photo by Stephane Corvaja/ESA via Getty Images)

It's a 30-day-old Echidna baby, known as a “puggle” – one of only 24 ever bred in captivity. The proud parents are Tippy and Pickle of Australia Zoo. The tiny baby, whose s*x has not yet been identified, hatched from a soft egg and will continue to develop and nurse inside Tippy's warm pouch. (Photo by Australia Zoo/Rex/Sipa Press)

Iraqis who have fled fighting between security forces and al-Qaida inspired militants in their hometown of Tal Afar arrive in a car at Germawa camp for displaced Iraqis, in a hot dusty plain in the largely-autonomous Kurdish area of Dahuk, 260 miles (430 kilometers) northwest of Baghdad Tuesday, June 17, 2014. (Photo by AP Photo)

A man photographs Anila Quayyum Agha's “Intersections” art work on the first day of ArtPrize at the Grand Rapids Art Museum in Grand Rapids, Mich. on Wednesday, September 24, 2014. (Photo by Emily Rose Bennett/AP Photo/The Grand Rapids Press)

NASA's DHC-3 Otter plane flies in Operation IceBridge-Alaska surveys of mountain glaciers in Alaska in this image released on September 18, 2014. Over the past few decades, average global temperatures have been on the rise, and this warming is happening two to three times faster in the Arctic. (Photo by Chris Larsen/Reuters/NASA/University of Alaska-Fairbanks)

A winter swimmer, wearing a Santa Claus hat to celebrate the upcoming Christmas, reacts as he plays on a frozen lake at a park in Shenyang, Liaoning province, December 22, 2014. The characters on the hat read: “Shenyang Winter Swimming”. (Photo by Reuters/Stringer)

Grey seal pup “Nikolaus” licks a window at the seal enclosure in Friedrichskoog, Germany, 19 December 2014. The pup was abandoned by his mother and would not have a chance at survival without human help. Nikolaus will be fed at the enclosure for two to three months until he has reached the minimum weight of 45 kilograms for being released. (Photo by Daniel Reinhardt/EPA)