Australia is not only the smallest continent but also Earth's largest island. But the land Down Under wasn't always so isolated; it was once part of a bigger supercontinent. So when did Australia become its own continent?
Australia's continental landmass measures about 2,300 miles (3,700 kilometers) from north to south and 2,485 miles (4,000 km) from east to west. Within its 2.97 million square miles (7.69 million square kilometers), Australia is home to the oldest known material of terrestrial origin on Earth: zircon crystals from the Jack Hills region of western Australia dating to about 4.4 billion years ago, according to a 2014 study in the journal Nature Geoscience.
