Visible from space, the world’s largest iceberg is headed towards a remote Antarctic island, threatening local animals. A23a, the trillion-ton megaberg, which is 40 meters tall, twice as broad as London, and viewable through satellites, could either collide with the island of South Georgia, or get trapped in ocean currents revolving around it. Past iceberg collisions on the island, which is home to King penguins and about half of the world’s population of Southern elephant seals, have led to mas