A masked reveller parades through the streets on the first day of the carnival season in Lucerne, Switzerland, 12 February 2015. In the background the well known Kappellbruecke bridge. (Photo by Alexandra Wey/EPA)

A member of a local swimming club holds a Russian national flag as he dives in at the start of a 24-hour swimming marathon near the western Siberian city of Barnaul March 29, 2014. Thirty members of the club will swim in turn during the event, held to mark Crimea becoming part of Russia, local media reported. (Photo by Andrei Kasprishin/Reuters)

A competitor scrambles in the mud under barbed wire during the Tough Guy Challenge 2009 at South Perton Farm on February 1, 2009 in Wolverhampton, England. The biannual event to raise cash for charity challenges thousands of international competitors to run through a gruelling set of 21 obstacles including water, fire and tunnels after a lengthy run at the start. (Photo by Christopher Furlong/Getty Images)

Six-month old female liliger cub Eva plays in snow with her mother Zita in the Zoo in Novosibirsk, Russia, Thursday, December 5, 2013. The cub's mother is Zita, a liger – half-lioness, half-tiger, and its father is a lion, Sam. (Photo by Ilnar Salakhiev/AP Photo)

“On March 8th activists celebrate International Women’s Day, which dates back to the early 20th century and has been observed by the United Nations since 1975. In the run-up to the event, Reuters photographers in countries around the globe took a series of portraits of women and their daughters. They asked each mother what her profession was, at what age she had finished education, and what she wanted her daughter to become when she grew up. They also asked each daughter at what age she would finish education and what she wanted to do in the future. The series of images offers an insight into the lives of women and girls around the world”. – Reuters. (Photo by Feisal Omar/Reuters)

Space Shuttle Discovery is towed from the shuttle landing facility to the orbiter processing facility at Kennedy Space Center on April 20, 2010 in Cape Canaveral, Florida. Discovery's landing attempts at KSC were scrubbed yesterday due to unacceptable weather conditions. Discovery is returning from a successful mission to the International Space Station. (Photo by Matt Stroshane/Getty Images). CAPE CANAVERAL, FL – APRIL 20 2010

Ukraine's Ruslana performs her song Wild Dance ands wins the Eurovision Song Contest on May 15, 2004 at the Abdi Ipekci Stadium, in Istanbul, Turkey. The event – hosted by last year's winners Turkey – also celebrates the 30th Anniversary of ABBA's win. (Photo by Christopher Furlong/Getty Images)