Timbuktu: A UN peacekeeper from Burkina Faso stands guard at the Djinguereber mosque, built in the 14th century, during a visit by a UN delegation on election day in Timbuktu, Mali, July 28, 2013. (Photo by Joe Penney/Reuters)

This artist's scoreboard displays a fictional game between Mars and Earth, with Mars in the lead. It refers to the success rate of sending missions to Mars, both as orbiters and landers. Of the previous 39 missions targeted for Mars from around the world, 15 have been successes and 24 failures. For baseball fans, that's a batting average of .385. The United States has had 13 successes out of 18 attempts, or a “batting average” of .722. NASA's Curiosity rover, set to land on the Red Planet the evening of Aug. 5, 2012 PDT (morning of Aug. 6 EDT), will mark the United States' 19th attempt to tackle the challenge of Mars, and the world's 40th attempt. (Image by NASA/JPL-Caltech)

U.S. Marines kick in a door while securing a building next to the main hospital in central Baghdad April 15, 2003, which will be used as a temporary Iraqi police headquarters. (Photo by Jerry Lampen/Reuters)

A customer buys a box of bullits and a target of Osama Bin Laden October 3, 2001 at Blue Ridge Arsenal in Chantilly, VA. Guns sales have risen across America since the September 11th terrorist attacks. (Photo by Mark Wilson/Getty Images)

“An egg case or egg capsule, colloquially known as a mermaid's purse or devil's purse, is a casing that surrounds the fertilized eggs of some sharks, skates, and chimaeras”. – Wikipedia. Photo: OBX Skate (Raja eglanteria) Egg Case – Mermaid's Purse. (Photo by altereye1)

“Car2go fleet is located throughout the greater downtown area and can be accessed on-demand or booked 24 hours in advance. The members may use the vehicle for as long as they like, without committing to a specific return time or return location”. – Wikipedia

Photo: A car2go employee shows how members can use a smartphone or iPad app to locate and reservec car2go vehicles March 22, 2012 in Washington, DC. Beginning March 24, car2go will offer the first free-floating car-sharing service in Washington and Portland, Oregon, where customers can use the smartphone app within the 34-square-mile “Home Area”. After paying a one-time $35 membership fee, drivers can then rent the Smart Fortwo vehicles by the minute, paying only for the time they use the vehicle, with discounted rates for hourly and daily use. (Photo by Chip Somodevilla/Getty Images)

Farmers herd a flock of ducks along a street towards a pond as residents drive next to them in Taizhou, Zhejiang province, June 17, 2012. (Photo by Reuters/China Daily)