A lookout on the ship HMS Endeavour spotted something amazing. Land appeared on the horizon after months at sea. It was April 19, 1770. Captain James Cook and his crew had found the east coast of a massive land. Today we call it Australia. Cook had sailed from England to observe a rare event in the sky. After that task, he headed south with secret orders. The British government wanted him to search for a mysterious southern land. For weeks, he saw nothing but ocean. Then the crew spotted tall cliffs and green forests. Cook sailed along the coast, making careful charts. He drew the shape of the land on maps. His crew collected plants and animals nobody in Europe had seen before. They found kangaroos, strange birds, and unusual plants. But this land was not empty. Aboriginal Australians had lived there for over 50,000 years. They watched Cook's ship from shore. Cook's maps changed how Europeans understood the world. Australia became a major part of the British Empire.