Extras
A long lost ancient cemetery opens the door to a unique period in Egyptian history.
Our skies are full of objects, natural and manmade, that are not as strange as you might think.
Getting the right bag to the right plane requires an ingenious system. Here鈥檚 how it works.
Area 51鈥檚 UFO myths became a cover for secret testing of cutting-edge military technology.
What does the government know about UFOs? Experts weigh in on the need to identify these objects.
Can scientists identify the man buried inside a mysterious coffin found under Notre Dame?
Fossils reveal how birds survived the killer asteroid and became today鈥檚 only living dinosaurs.
Follow the race to build a world-class airport on the site of one of America鈥檚 busiest flying hubs.
Atomic clocks use quantum physics and the resonant frequency of atoms, like cesium, to define time.