A cow, which escaped from a truck, attacks a farmer trying to catch it in Liangdun village of Nangang township, Anhui province December 15, 2013. The 700 kilogram (1,543 lb) cow attacked several farmers before being shot dead by policemen, local media reported. (Photo by Reuters/China Daily)

A couple looks at their flooded street from behind their home's window in La Plata, in Argentina's Buenos Aires province, where at least 35 people were killed by flooding overnight, on April 3, 2013. (Photo by Natacha Pisarenko/Associated Press)

A waitress displays a plate of animal penises and testis at the Guolizhuang pen*s Restaurant on September 7, 2007 in Beijing, China. The restaurant offers more than 30 types of animal-pen*s dishes which can cost from 500 yuan (76.99 USD) up to 90,000 yuan (13,857.67 USD). It is believed that eating an animal's pen*s can strengthen a man's sexual ability. (Photo by Feng Li/Getty Images)

A demonstrator carries a placard reading “One more day of reflection” as she dances with others at Sol Square on May 21, 2011 in Madrid, Spain. A growing number of angry Spaniards have, encouraged by youth groups and social media campaigns, taken possession of the Sol square setting it up with tents and kitchens ahead of Sundays regional and municipal elections held in Spain. (Photo by Jasper Juinen/Getty Images)

“NASA's Pathfinder, Pathfinder Plus, Centurion and Helios Prototype were an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as “atmospheric satellites”, to perform atmospheric research tasks as well as serve as communications platforms”. – Wikipedia

Photo: The solar-electric Helios Prototype flying wing is flies over the Hawaiian islands of Niihau and Lehua during the first solar-powered test flight July 14, 2001 from the U.S. Navy's Pacific Missile Range Facility on Kauai, HI. The 18-hour flight was a functional checkout of the aircraft's systems and performance in preparation for an attempt to reach sustained flight at 100,000 feet altitude later in the summer. (Photo Courtesy of NASA/Getty Images)