People crowd onto 42nd Street as they take photos of the “Manhattanhenge” phenomenon in the Manhattan borough of New York July 11, 2014. Manhattanhenge, coined by astrophysicist Neil deGrasse Tyson, occurs twice a year, when the setting sun aligns itself with the east-west grid of streets in Manhattan. (Photo by Carlo Allegri/Reuters)

Izzy Paskowitz helps Nixee Grace Chanowsky, 4, catch a wave Monday, August 18, 2014 at Wrightsville Beach, N.C. during the Annual Surfers Healing event for children with autism. Hundreds of people made their way to the beach to watch and cheer on the camp that was founded by Israel and Danielle Paskowitz. (Photo by Mike Spencer/AP Photo/The Star-News)

Holly Spring, a New Zealand photographer, says she is inspired by her daughter Violet, who was born with multiple ailments; Hirschsprung’s Disease, a blockage of the large intestine and Symbrachydactyly, a limb abnormality. The series was designed to show her daughter that she “can live a life without obstacles”. (Photo by Holly Spring)

People protest for greater action against climate change during the People's Climate March on September 21, 2014 in New York City. The march, which calls for drastic political and economic changes to slow global warming, has been organized by a coalition of unions, activists, politicians and scientists. (Photo by Andrew Burton/Getty Images)

Actors dressed up as zombies walk around while posing for photos with passers-by in New York's Times Square on Friday, October 10, 2014 as a promotion for the season premiere of AMC's “The Walking Dead” this Sunday, October 12, 2014. (Photo by Gordon Donovan)

Virgin Galactic's new spaceship N202VG (bottom L) is seen behind the WhiteKnightTwo carrier aircraft mothership (front), which landed safely after splitting from SpaceShipTwo, in a hangar at Mojave Air and Space Port in Mojave, California, November 4, 2014. (Photo by Lucy Nicholson/Reuters)

David Rawcliffe, house and monument steward at the National Trust's Chedworth Roman Villa cleans a Roman mosiac in the new environmentally-controlled conservation shelter on March 19, 2012 near Cirencester, England. Opened this month, the multi-million pound building allows visitors to walk on suspended walkways just above the 1600-year-old Roman floors and to see recently excavated mosaics not seen for 150 years, with more to be uncovered over the coming year. (Photo by Matt Cardy/Getty Images)

Salt-resistant plants grow in sand made up of small fish bones on the shore of the Salton Sea before sunrise in an area where a controversial development would create a new town for nearly 40,000 people on the northwest shore of the biggest lake in California, the Salton Sea, on March 21, 2012 south of Mecca, California. (Photo by David McNew/Getty Images)