James Cook almost discovered Antarctica

Cook came quite close to discovering Antarctica during his first expedition, even though he may not have discovered the fabled Great Southern Continent. In 1773, he made the first known crossing of the Antarctic Circle, after which he annexed South Georgia Island to the Crown. Cook's voyage traveled around the world at an extreme southern latitude, and on January 17, 1773, it became one of the first to pass the Antarctic Circle. Resolution and Adventure split apart in the icy fog. Furneaux traveled to New Zealand, ran afoul of the Mori, and ultimately sailed back to Britain, while Cook resumed his exploration of the Antarctic, arriving at 71°10'S on January 31, 1774.

Cook just missed coming into contact with the Antarctic continent before turning his ship for Tahiti to replenish. In a second futile attempt to locate the alleged continent, he then resumed his southerly voyage. He traveled with Omai, a young Tahitian who turned out to be somewhat less knowledgable about the Pacific than Tupaia had been on the earlier stage of the journey. Cook stopped at the Friendly Islands, Easter Island, Norfolk Island, New Caledonia, and Vanuatu during his 1774 return trip to New Zealand. Cook and his team ultimately made four trips around the Antarctic Circle. During one of his voyages, he came very close to seeing Antarctica itself, but pack ice caused him to turn around before he could get any closer, making the White Continent an unattainable goal.