Nuns watch a giant screen showing a helicopter with Pope Benedict XVI onboard in St. Peter's Square, at the Vatican,Thursday, Feb. 28, 2013. The 85-year-old German Pope Benedict is ste

 

              Nuns watch a giant screen showing  a helicopter with Pope Benedict XVI onboard in St. Peter
Nuns watch a giant screen showing a helicopter with Pope Benedict XVI onboard in St. Peter's Square, at the Vatican,Thursday, Feb. 28, 2013. The 85-year-old German Pope Benedict is stepping down on Thursday evening, the first pope to do so in 600 years, after saying he no longer has the mental or physical strength to vigorously lead the world's 1.2 billion Catholics. (AP Photo/Dmitry Lovetsky)