Achievement unlocked: "We have arrived!" Our @OSIRISREx mission reached asteroid Bennu, where it will spend almost a year mapping and studying to find a safe location to collect a sample. Watch: https://t.co/zI282xjLzc pic.twitter.com/VMPs7SIfSf — NASA (@NASA) December 3, 2018

OSIRIS-REx launched in 2016 and its mission is to collect a sample from Bennu and return it back to Earth for study. The spacecraft will spend more than a year surveying and mapping the asteroid, and researchers will use that information to select a sample site. Once they do, OSIRIS-REx will gently contact and bounce off of the surface of Bennu, collecting a sample of the asteroid's surface as it does. The spacecraft will then begin heading back to Earth in 2021 and is scheduled to deliver its sample, if all goes well, in September 2023.

In January, OSIRIS-REx took a picture of Earth and the moon from over 3 million miles away, and last month, NASA performed a successful test of the robotic arm that will collect the samples from Bennu's surface.