The youngest and oldest mountain ranges on Earth: It might surprise you to know that mountains aren't static; they are constantly being formed and weathered away over millions, even billions, of years ...

Mountaineers will have to contend with much more unpredictable conditions. Climbing Mount Everest is one of the most difficult feats known to humankind, but the treacherous expedition is getting even ...

The 29-year-old climber was hung suspended on a near-vertical ice wall, his crampons loosely gripping the frozen slope. Why?