A mass pillow fight in Trafalgar Square in central London on April 5, 2014 on International Pillow Fight Day. (Photo by Jane Scanlan)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

Punks gather in Blackpool for the annual Rebellion Punk Rock Festival on August 8, 2014 in Blackpool, England. This weekend a clash of musical cultures hits the famous seaside town as pogoing punks attending the annual Rebellion Festival at The Winter Gardens come shoulder to shoulder with traditional holidaymakers and seasiders. (Photo by Christopher Furlong/Getty Images)

Historical reenactor Troy Kotz poses with a mug of wassail in the parlor of the Guyon-Lake-Tysen House during the annual Candlelight Tour of Historic Richmond Town, Saturday, December 13, 2014, in the Staten Island borough of New York. The annual event lets visitors experience an authentic Victorian Christmas. This image was made using the TinType by Hipstamatic iPhone app. (Photo by Chad Rachman/New York Post)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

From rural life in India to a chick growing inside its embryo and a sea turtle eating a purple jellyfish, the Society of Biology has released their stunning photography competition shortlist. Here: “Spectral Tarsier”. Tangkoko, Northern Sulawesi, Indonesia: Spectral tarsier by Wolfgang Weinhardt. (Photo and caption by Wolfgang Weinhardt/UK Society of Biology Photography Award 2014)

A cat is examined by the jury during the first day of the Super Cat Show 2014, on November 8, 2014 in Rome, Italy. The Super Cat Show 2014, which takes place on the 8th and 9th of November, involves the participation of 800 cats of different breeds from all over the world. (Photo by Giorgio Cosulich/Getty Images)

Spectators dressed as leprechauns attend St Patrick's Day parade in Dublin on March 17, 2014. (Photo by Peter Muhly/AFP Photo)