Again Recalling a conversation with John Glenn a decade ago. It was just after the launch of the first shuttle mission to follow the Challenger disaster. Even then, Glenn longed to return to space. But time and tourists are taking their toll, and not enough is being done to save them. Secrets of the Grand Canyon One of the best places to study North America's continental past is the Grand Canyon.
Some geologists seek to interpret the storied canyon walls.
Tracking Arctic Dinosaurs Northern Alaska wasn't always so cold and inhospitable. About 100 million years ago, it was lush, with dinosaurs wandering the region. They left behind some footprints. Bold Dreams Brought to Life Soaring into space expanded mankind's reach, and allowed us all to dream big. A look back at what 40 years of NASA has meant to us.