The asteroid Torifune, recently photographed by the Hayabusa2 probe, displays an astonishing peanut shape typical of contact binary asteroids. This structure indicates that two celestial bodies merged over time, offering scientists a natural laboratory to study planet formation. This close flyby, conducted on July 5, 2026, marks a new step in Japanese space exploration.
Asteroid Torifune seen by Hayabusa2's optical navigation camera on July 5, 2026.
Credit: JAXA
The Japan Aerospace Exploration Agency (JAXA) orchestrated this high-speed flyby about 62 million miles (100 million kilometers) from Earth. The probe used its optical camera to capture detailed images of Torifune, a 490-yard (450-meter) rock that orbits the Sun in 383 days. This risky maneuver, as little information was available about the asteroid, was described as a delicate operation by the science team.
The data collected is not limited to images. The TIR infrared instrument measured surface temperatures, revealing warm areas exposed to the Sun and cooler regions in shadow. This information helps understand the asteroid's composition and structure, particularly its porosity and thermal conductivity. Torifune belongs to the Apollo group, a family of near-Earth asteroids.
Infrared view of Torifune showing temperature variations.
Credit: JAXA This encounter was not planned in Hayabusa2's initial mission. Launched in 2014, the probe first visited the asteroid Ryugu, from which it collected samples in 2020. Analysis of these materials detected all five nucleobases of DNA and RNA, providing clues about the emergence of life on Earth. After this success, Hayabusa2 continued its journey toward new targets.
The next objective is asteroid 1998 KY26, a small body only 36 feet (11 meters) in diameter, comparable to the one that exploded over Chelyabinsk in 2013. The probe is expected to reach it in 2031, attempting a flyby and then contact. This extended mission aims to study the properties of the smallest asteroids, whose structure is still poorly understood.
Size comparison between Ryugu and the next target 1998 KY26.
Credit: ESO/M. Kornmesser
The images of Torifune add to a fine series of successes for Hayabusa2, which has logged nearly twelve years of mission. The perseverance of Japanese engineers and the robustness of the probe allow for the accumulation of valuable data on the diversity of asteroids. Each new observation refines our understanding of the Solar System's evolution.