Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more . CNN  —  The biggest iceberg in the world, named A23a , appears to have run aground after drifting around the Southern Ocean near Antarctica since 2020. Weighing nearly a trillion metric tonnes (1.1 trillion tons), A23a has come to a stop off the island of South Georgia, a British Overseas Territory in the southern Atlantic Ocean, according to a