Measuring approximately 500 meters in diameter, Bennu has long been of interest to scientists because of its potential to teach us more about the earliest days of the solar system.
It is also significant due to its potential to collide with the Earth at some point in the future, however recent estimates have generally played down the likelihood that this will happen.
Back in September 2016, NASA sent a spacecraft – Osiris-Rex – to rendez-vous with Bennu.
After arriving there in 2018, it spent over two years investigating the asteroid and collecting samples.
Now, having completed its task, the spacecraft has turned back towards the Earth and is heading for home.
Its precious cargo will be NASA’s largest haul of off-world material since the astronauts returned samples of the Moon during the Apollo program.
If all goes well, the spacecraft will reach Earth in September 2023.
“I’ve been working on getting a sample back from an asteroid since my daughter was in diapers and now she’s graduating from high school, so it’s been a long journey,” said NASA project scientist Jason Dworkin.