Captain Cook’s second voyage was to find out whether Terra Australis really existed or not.
On his first voyage, he discovered the southeast coast of Australia. On the same trip, he also mapped them. However, the ‘hypothetical’ Terra Australis still remained an unsolved mystery. Shortly after his return from the first voyage, Cook was promoted to the rank of commander.
Later he was commissioned for a second voyage. Cook commanded the HMS Resolution on this voyage. During this voyage, he became the first explorer to sail into the Antarctic Circle. He circumnavigated Antarctica at the very limits of the ice shelf. But he did not make a landfall on the mainland of Antarctica, as he had to sail towards Tahiti to resupply his ship.
Cook visited Easter Island, the Marquesas, the New Hebrides, New Caledonia, and the Tonga Isles. Cook was able to find these comparatively smaller lands in the Pacific, and to map them. After sailing through all its likely locations, Cook confirmed that there was no land called Terra Australis.
Thus, Cook became the first to officially prove that the existence of Terra Australis was a myth.