Hayabusa heading home

Japan's Hayabusa-2 spacecraft has departed from the asteroid Ryugu with samples of its soil and begun its year-long journey back to Earth. 

Hayabusa-2 was launched in 2014. Three and a half years later, it reached the asteroid Ryugu, located about 300 million km (190 million miles) from Earth.  The spacecraft is expected to return to Earth in December 2020, dropping a capsule containing the rock samples in the South Australian desert.  

Following its arrival in June 2018, the spacecraft made touchdowns twice, collecting data and rock samples from the Ryugu - a primitive space rock leftover from the early days of the Solar System

Scientists believed these would be more pristine samples, since they would not have been exposed to the harsh environment of space. They were the first underground samples collected from an asteroid in space history.

While asteroids are some of the oldest objects in space, Ryugu belongs to a particularly primitive type of space rock, and may contain clues about the conditions and chemistry of the early days of the Solar System - some 4.5 billion years ago.