Thirteen women who trained as astronauts never reached their goal of spaceflight, but cleared the path for others | EXPLORATIONS

Each year, millions of people visit the Vatican Museums to see works by artists such as Michelangelo and Raphael | EXPLORATIONS

The park in Colorado has more than 5,000 ruins from the time of the Ancestral Puebloans | EXPLORATIONS

Also, scientists relaunch a project (shown) aimed at getting the public involved in the search for alien life | EXPLORATIONS