By accident
That was Captain James Cook on his second voyage to the Pacific Ocean.
The first European was Captain James Cook.
Quite simply, he returned. The god they believed Captain Cook to be was not supposed to return almost immediately after leaving the islands, which was what Cook did.
No, Captain James Cook discovered Tahiti. Captain Bligh was going to Tahiti to deliver Breadfruit.
The English sea captain Captain James Cook was most known for being the first European to find the eastern coast of Australia, as well as eliminating the rumor of a great southern continent among with other things.
Because he was the first person to find Australia and anyway's it's also history.
James Cook (not a captain a this stage, but a Lieutenant) explored the eastern coast of Australia in the HMS Bark Endeavour. He did not 'find' or discover Australia, as the Dutch had already discovered the land over 150 years before Cook arrived.
James Cook was able to determine that New Zealand was not a continent because he circumnavigated the islands, sailing around the islands and charting them as he went.
James Cook did not actually sail into Sydney Harbour. He sailed into Botany Bay, 8km south, originally naming it "Stingray Harbour".
The first voyage of Captain James Cook on the HMS Endeavor was a south Pacific Ocean expedition to observe the 1769 transit of Venus across the Sun. A dual purpose was to find evidence of an unknown southern land.
Not a thing. Captain James Cook was prevented from reaching the Antarctic cotinent because of the pack ice, and the fact that his sails kept freezing. He was only the first European to cross the Antarctic circle, doing so twice.
You can find it on Wikipedia, or go to google and search James Cook image.