Revellers attend the Victorian Picnic during the Wave and Goth festival in Leipzig, Germany, May 22, 2015. The annual festival, known in Germany as Wave-Gotik Treffen (WGT), features over 100 bands and artists in venues all over the city playing Gothic rock and other styles of the dark wave music subculture. One of the biggest of its kind, the event attracts a regular audience of up to 20,000, the organisers said. (Photo by Hannibal Hanschke/Reuters)

Girls accompany grooms as they sit separate from the brides during a mass wedding for 150 couples in Beit Lahiya town in the northern Gaza Strip July 20, 2015. The wedding was funded by al-Basheer Society for Relief and Development. (Photo by Suhaib Salem/Reuters)

People slide down a 1,082 feet (330 metre) long inflatable water slide in Hong Kong, China August 22, 2015. (Photo by Tyrone Siu/Reuters)

A performer from the Academicos do Grande Rio samba school dances during carnival celebrations at the Sambadrome in Rio de Janeiro, Brazil, early Monday, February 16, 2015. (Photo by Silvia Izquierdo/AP Photo)

A woman sits as she gets a tattoo on her leg during the annual Panama City Ink Fest in Panama City August 16, 2015. (Photo by Carlos Jasso/Reuters)

An Indian woman dressed as Hindu Goddess Kali participates in a “Shivratri” procession in Allahabad, India, Thursday, Feb. 27, 2014. “Shivaratri”, or the night of Shiva, is dedicated to the worship of Lord Shiva, the Hindu god of death and destruction. (Photo by Rajesh Kumar SinghAP Photo)

NASA handout photographs from the various Apollo missions are shown in this combination photograph. The photographs are some of more than 12,000 from NASA's archives recently aggregated on the Project Apollo Archive Flickr account. (Top L) David R. Scott, command module pilot, stands in the open hatch of the Command Module during the Apollo 9 mission March 6, 1969. (Top centre) Edwin "Buzz" Aldrin Jr.walks on the surface of the moon during the Apollo 11 mission July 20, 1969. (Top R) Neil Armstrong, Apollo 11 commander, is pictured inside the Lunar Module during the Apollo 11 mission July 20, 1969. (Bottom L) Alan Bean holds a container filled with lunar soil collected during the Apollo 12 mission November 19, 1969. (Bottom centre) Scientist-astronaut Harrison Schmitt rides in the Lunar Roving Vehicle during the Apollo 17 mission December 13, 1972. (Bottom R) Harrison Schmitt stands next to a huge, split boulder during the Apollo 17 mission December 13, 1972. (Photo by Reuters/NASA)

A model wears a floral head dress as she promotes a chain of garden centres at the Royal Horticultural Soceity's Chelsea Flower Show in London, Britain, May 18, 2015. (Photo by Toby Melville/Reuters)