Curious Kids: how and when did Mount Everest become the tallest mountain? And will it remain so?

On Oct. 15, American climber Jim Morrison became the first person to ski down Mount Everest's most challenging route, the Hornbein Couloir, a narrow and steep gully just over 1,100 feet below the mountain's summit. The feat is the subject of an upcoming National Geographic documentary which is currently in production. Morrison took on the challenge with renowned filmmaker and mountaineer Jimmy Chin, director of 2018's "Free Solo," which won an Oscar for documenting rock climber Alex Honnold's fr