After departing from a distant asteroid, Japan's Hayabusa2 spacecraft started its year-long journey home after successfully completing its mission to bring back soil samples and data that could provide clues to the origins of the solar system.<br />'' <br />'' The Japan Aerospace Exploration Agency says the spacecraft left its orbit around the asteroid Ryugu, about 300 million kilometres from Earth.<br />'' <br />'' Hayabusa2 made two touchdowns on the asteroid and successfully collected data and samples during its 1½-year mission since arriving there in June 2018. The spacecraft is expected to return to Earth in late 2020 and drop a capsule containing the precious samples in the Australian desert.<br />'' <br />'' Scientists hope the samples contain carbon and organic matter that could explain how they are related to Earth. <br />