Vatican may limit visitors to the Sistine Chapel

While 75 percent of the planet is a relatively unchanging shade of ocean blue, the remaining surface goes through stages of green. In this NASA/NOAA imagery capturing April 2012 to April 2013, the darkest green areas are the lushest in vegetation, while the lightest could be snow covered, drought impacted or just un-vegetated rock.

In Sierra Buttes, Calif., two boys hiked up a jagged cliff and ended up stranded 8,000 feet up. The California Highway Patrol sent a chopper and had to lower a harness to carry them to safety, since climbing down was not an option. Scott Pelley reports.

In a pilot program in Tucson, Ariz., aerospace and defense contractor Raytheon is spending $100 million in hopes of inspiring future engineers and technology professionals. Anthony Mason reports.

Led by state Senate President John Morse, Colorado passed new gun control laws in March. Now, opponents of the law are trying to remove Morse from office. Barry Petersen reports.

President Obama's plan for leaving Afghanistan reached a new milestone Tuesday as the Afghan military officially took responsibility for the country's security. The White House also said it would try again to hold peace talks with the Taliban. Major Garrett reports.

In an interview with "CBS This Morning" co-host Charlie Rose, President Barack Obama defended the NSA surveillance programs and his recent decision to provide military support to the Syrian opposition in that country's civil war.

Daoud Gilani was the classic example of a terrorist sleeper agent. Born in Washington, D.C., he became radicalized and changed his name to David Coleman Headley. John Miller explains how he traveled the world on a U.S. passport, setting up terrorist attacks before he was eventually caught.

General Keith Alexander said the NSA's surveillance programs have helped stop more than 50 potential strikes since the 9/11 attacks. At least 10 of them involved homeland-based threats. Bob Orr reports.

The worst fire in Colorado's history, the Black Forrest fire, has consumed 24 square miles. While the flames have finally died down, the danger is not over yet. Firefighters still must extinguish embers deep in the forest floor. Barry Peterson reports.

During the past eight years, Iran has refused to open its nuclear program up to international scrutiny. But on Monday, President-elect Hassan Rowhani said Iran was "ready to show more transparency to the world." Elizabeth Palmer reports.

The civil war in Syria is starting to impact neighboring countries. The United States is sending the Assad dictatorship a message by holding joint military exercises with Jordan. Clarissa Ward reports.

Last summer, Jack and Jasinda Wilder and their five children were deep in a financial crisis. In desperation, the couple self-published a series of steamy romance novels that started picking up followers online. In a year, the rookie authors had sold more than a million e-books. Anthony Mason reports.