Hayabusa 2’s main mission is effectively up to now, now. JAXA’s asteroid sampling spacecraft rendezvoused with asteroid Ryugu again in June 2018. It studied the asteroid for 1.5 years and gathered a pattern which was returned to Earth in December 2020.
After that profitable endeavour, Hayabusa 2 was despatched on its solution to go to different targets, although one other sample-return shouldn’t be attainable. It is on its solution to go to a tiny asteroid referred to as 1998 KY26, a near-Earth object (NEO) solely about 11 meters in diameter. However on its method, it additionally flew previous one other asteroid named Torifune (98943 Torifune).
Floor-based observations confirmed that Torifune is a near-Earth asteroid (NEA) measuring about 450 meters in diameter. It is an S-type asteroid, which means its a stony-type or siliceous-type. These are high-density objects that make up about 17% of the asteroid inhabitants, making them the second commonest sort after carbonaceous C-type asteroids.
*These are two totally different top-down methods of envisioning Hayabusa 2 and asteroid Torifune. The left panel reveals a view in a body that rotates with Earth’s orbit. The appropriate panel reveals a stationary body. Picture Credit score: By Authentic by Hirabayashi et al. 2026, modified by Nrco0e – Modified from Determine 2 of CC BY 4.0,
Hayabusa 2 started taking a look at Torifune in June with its Optical Navigation Digicam – Telescopic (ONC-T). The ONC-T instantly imaged Torifune on June twentieth for navigation functions.
Then on July fifth, Hayabusa 2 got here to inside about 800 meters of the asteroid. It used ONC-T to seize photographs of Torifune that exposed particulars about its floor. Whereas ground-based observations confirmed the asteroid was elongated, hinting at its contact binary nature, solely these photographs affirm it. Involved binaries, two separate asteroids orbited a standard middle of mass till they spiralled in in the direction of one another and joined into one. Contact binary asteroids aren’t anticipated to be uncommon.
Starting at about one hour earlier than closest strategy, Hayabusa 2 additionally noticed Torifune with its different devices, the NIRS3 (Close to-Infrared Spectrometer), TIR (Thermal InfraRed Imager), and LIDAR (Mild Detection and Ranging).
*Hayabusa 2 additionally imaged asteroid Torifune with its Thermal InfraRed Imager (TIR). This TIR picture is from about 10 km away. Picture Credit score: JAXA, Maebashi Institute of Know-how, Chiba Institute of Know-how, The College of Aizu, Hokkaido College of Schooling, AIST*
Hayabusa 2 was travelling very quick throughout this flyby. Its relative pace was 5 km/s (3.1 mi/s), making navigation and picture capturing difficult. It has lower than half of its xenon propellant remaining, sufficient to energy its ion thrusters to fulfill Torifune and 1998 KY26, however not sufficient for any additional maneuvers.
Hayabusa 2’s subsequent milestone will probably be in December 2027 when it swings previous Earth. Then in June 2028, it should swing by Earth once more. That may set it up for its rendezvous with 1998 KY26 in July 2031.
The precise nature of 1998 KY26 is not clear. Observations in optical and radar counsel that it is a water-rich asteroid, and because it’s identified to be a fast-rotator, it is nearly actually one single chunk of rock reasonably than a rubble pile asteroid. It may additionally doubtlessly be an X-type asteroid, which is a catch-all time period that encapsulates objects that look related by a telescope however are composed of various supplies.
All of Hayabusa 2’s information from its flyby of Torifune has not but reached Earth, so these are preliminary outcomes. JAXA will launch extra within the close to future.
