The Japanese Hayabusa2 spacecraft has completed one of its most exciting challenges yet: On Thursday evening, it touched down on the asteroid Ryugu, fired a tantalum bullet into the rocky surface, and ascended back into orbit around the tiny world, according to updates from the mission’s English-language Twitter account.
During its brief contact with the asteroid, the spacecraft should have attempted to collect rock samples kicked up by the bullet, the Planetary Society explained. The return of these samples to Earth is a major goal of the mission.
Japan Aerospace Exploration Agency (JAXA) has been preparing for Hayabusa2 to make contact with the asteroid for months. The touchdown was previously delayed after scientists found the asteroid’s surface to be rougher than they had initially anticipated. While scientists had originally thought Ryugu’s surface would be a “powdery fine regolith,” the MASCOT and MINERVA-II1 rovers dropped by the spacecraft were greeted instead by larger-than-expected gravel.
Though its original touchdown date of October was delayed, mission scientists were able to conduct tests back here on Earth to further prepare for Hayabusa2’s eventual contact with the asteroid. In addition to making sure that the spacecraft would still be able to collect its surface samples, mission scientists were also able to reassess its landing site.
Hayabusa2 launched in 2014 and spent four years travelling to its target. The spacecraft successfully reached Ryugu in June of last year, at which time mission scientists determined the landing sites for its rovers.
NASA has its own asteroid mission underway: The spacecraft OSIRIS-Rex arrived at the asteroid Bennu in December 2018, and has already taken some breathtaking images of the object’s south pole.