A New Zealand air force plane made a rare wintertime landing on an ice runway in Antarctica today on a mercy mission to evacuate a seriously ill American worker, officials said.

The world’s biggest iceberg has begun moving again, nearly three months after it ran aground, threatening penguin breeding colonies and blocking ships supplying food and fuel to Antarctic research stations, officials said today.

The world’s largest iceberg appears to have run aground, posing more problems to scientific bases on Antarctica and penguin colonies, where tens of thousands of chicks face starvation.