The Hayabusa2 spacecraft completed its flyby of the asteroid Torifune over the weekend, according to a statement issued by Japan’s space agency.
The intrepid Japan Aerospace Exploration Agency (JAXA) probe’s visit marks one of the closest approaches a spacecraft has ever made to a distant asteroid, and follows Hayabusa2’s successful 2020 mission to return samples from the asteroid Ryugu.
Information obtained during the flyby, which occurred on Sunday, may help to provide new insights into both the composition of these ancient space rocks drifting through our solar system, as well as how to defend our planet if one large enough to pose a significant risk were ever to make its way here.
Hayabusa2 completes a Historic Close Encounter
At approximately 6:30 p.m. Japan Standard Time on Sunday, Hayabusa2 passed the asteroid while traveling at speeds approaching 5 kilometers per second.
The recent achievement comprises part of the probe’s extended mission, which will include a future visit to the small asteroid 1998 KY26, which is expected to occur in 2031.
Over the weekend, the spacecraft’s flyby of Torifune helped to showcase Hayabusa2’s orbital guidance systems, as well as its ability to monitor asteroids and collect data to aid in the protection against potentially dangerous near-Earth objects (NEOs) before they become a threat, the Japanese Times reported.
Fortunately, asteroids with life-threatening potential only reach the Earth every few hundred years on average, and none currently being monitored by space agencies around the world are believed to represent any imminent threat.
Close Approach, not a Collision
One of the most difficult aspects of flybys like the one on Sunday involves the speeds at which spacecraft are moving, which can make avoiding a collision with the asteroid complicated. This is partly because of their dark coloration, which prevents visual confirmation of their location until just days before the flyby occurs, leaving only a small window for planning and preparation.
In a statement, Japan’s space agency said that these difficulties mean “that the flyby operation is similar to orbit-inducing technologies used to collide a spacecraft with an asteroid.”
If such technologies were to be used for planetary defense in the future, such a direct collision would be the goal, thereby aiming to set any potentially dangerous NEOs off course and keep Earth out of their line of fire.
Future Opportunities
In addition to the probe’s 2031 visit to 1998 KY26, JAXA officials say that additional opportunities for future reconnaissance will be likely, and that Sunday’s flyby served as an important dress rehearsal in that regard.
Additionally, data obtained from the flyby will be useful in helping JAXA officials and other space agencies around the world to know what to expect should a planetary defense effort become a requirement at any time in the future.
Once Hayabusa2 reaches 1998 KY26 in the early 2030s, it will mark the first time a spacecraft has engaged in close-range explorations of such an asteroid, which is currently estimated to be approximately 30 meters in diameter.
Additional details about the Hayabusa2 mission can be found at JAXA’s website.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.