On August 18, 2012 the infection spreads again as the undead hordes shamble through Vancouver in search of brains. The annual Zombie Walk has been going on for years and each year gets bigger and bigger. (Photo by Gord Gallagher)

The antennas of the European Southern Observatory's Atacama Large Millimeter/Submillimeter Array, also known as ALMA, are set against the splendor of the Milky Way in this picture by Babak Tafreshi. Construction of the full ALMA array is due to be completed in Chile's Atacama Desert in 2013, but the facility is already making scientific observations with a partial array of antennas. (Photo by ESO/B. Tafreshi/TWAN)

“The Last Pollen Spore Preparing to Leave a Ladybug Trying to Hold On, Because It Didn't Want to Be Alone”. Photo by Hiep Nguyen Hoang (Hanoi, Vietnam). Photographed in Hanoi, Vietnam, April 2012.

A clock showing a countdown to the start of the London 2012 Olympics is unveiled on March 14, 2011 in London, England. The clock is starting five hours from midnight when 6.6 million tickets for the Olympics will become available and 500 days before the Games start. There is a six-week window to apply for tickets on the London 2012 website.

Singer Kevin Lyttle (C) performs during the Premier Beverage: Jocktails 2012 Orlando at the Orlando Magic Experience Center on February 24, 2012 in Orlando, United States. (Photo by Gerardo Mora/Getty Images for Premier Beverage Company)

Competitors take to the streets of the capital in fabulous fancy dress costumes during the Virgin London Marathon 2012 on April 22, 2012 in London, England. (Photo by Mirror.co.uk)