A Japanese space probe the size of a household refrigerator has flown within a few kilometers of a distant asteroid, part of an international effort to test whether humanity could one day deflect a space rock headed for Earth.
The mission, run by the Japan Aerospace Exploration Agency (JAXA), sent the probe close to the asteroid 1998 KY26. The flyby took place on December 10, 2024, at a distance of about 2.5 kilometers from the object's surface.
A tiny target millions of kilometers away
The asteroid 1998 KY26 is small, only about 30 meters across. It orbits the sun at a distance that varies between roughly 100 million and 150 million kilometers from Earth. The probe, named Hayabusa2, launched in 2014 and has already visited another asteroid, Ryugu, where it collected samples and returned them to Earth in 2020.
After that success, JAXA extended the mission. The probe fired its ion engines to change course and head toward 1998 KY26. The flyby was the closest approach of the extended mission. The probe took images and collected data as it passed.
Why local people cared about a distant rock
In Japan, the mission drew attention because it builds on the country's growing reputation in deep space exploration. Hayabusa2 is already famous for bringing asteroid material back to Earth. Now, by targeting a different type of asteroid, scientists hope to learn more about the variety of objects that could pose a threat.
Asteroid 1998 KY26 is classified as a fast rotator, spinning once every 10 minutes. It is also thought to be a rubble pile, a loose collection of rocks held together by gravity. Understanding how such objects behave is key to planning any future deflection mission. If a large asteroid were on a collision course with Earth, knowing its composition could determine whether a kinetic impactor, like NASA's DART mission, would work or simply push the rubble apart.
A test for planetary defense
The flyby was not just about science. It was also a test of navigation and tracking capabilities. JAXA engineers had to guide the probe to within a few kilometers of a target they could barely see from Earth. The asteroid is so small and dark that it is difficult to observe with ground telescopes. Successfully reaching it demonstrates that Japan can conduct precision maneuvers in deep space, a skill essential for any future planetary defense mission.
The data from the flyby will take months to analyze. But the mission has already shown that a small, relatively inexpensive probe can be repurposed for asteroid defense work. Hayabusa2 is now heading toward its next target, another asteroid, for a flyby in 2026.
This mission adds a practical layer to the global conversation about protecting Earth. It proves that existing spacecraft, built for other purposes, can be redirected to study potentially hazardous objects. The work done by JAXA and its partners offers a real, tested capability, not just a theoretical plan.
