These sports are considered adventure travel par excellence. Extreme ski consists of going down quite a steep mountain with nothing but your skis. People practicing this activity have to use this technique in its maximum expression, giving priority to safety rather than to downhill speed.
Approximately 65 million years ago, a large percentage of vegetables and animals suddenly became extinct. It was in the late Cretaceous period and there are various theories about it. Some scientists attribute this event to a gradual process that finally led to selective extinction. Others assert that a catastrophe, such as an asteroid hitting the Earth, caused these species mass extinction.