The China National Space Administration’s probe first detected Kamo’oalewa on June 6, 2026, after undergoing multiple orbital adjustments in deep space. The asteroid orbits the sun in a path nearly identical to Earth’s, moving in near-synchronous motion that makes it a relatively accessible celestial body.
Kamo’oalewa has an average diameter of only about 41 meters and rotates at high speed, meaning the spacecraft must achieve stable contact and collect samples within a limited time frame. Tianwen-2 is equipped with multiple cameras with different focal lengths, switching between a narrow-field-of-view camera and a wide-field-of-view camera depending on the situation. It also carries a detachable camera that will be used during sample collection. Because the probe’s orientation must be finely adjusted when capturing images, seizing these limited windows is an extremely difficult task.
If the mission gathers samples, it will release them in a capsule during an Earth flyby in November 2027. The probe also plans to conduct more detailed scientific observations of Kamo’oalewa’s shape, material composition, and internal structure.
“It is highly likely to contain primordial information from the early days of the solar system’s formation, and it holds great scientific value for studying early material composition, formation processes, and evolutionary history,” said Han Siyuan, deputy director of the Lunar and Space Exploration Engineering Center and spokesperson for the Tianwen-2 mission. A successful sample return would mark another achievement in asteroid sample return, following Japan’s Hayabusa and Hayabusa2 missions, the first to return asteroid samples to Earth, and NASA’s OSIRIS-REx mission.
The asteroid’s origins remain contested. Researchers previously theorized that Kamo’oalewa is a fragment of the moon blown away by an asteroid impact millions of years ago, a widely accepted explanation because the spectrum of its reflected light closely resembles that of silicate minerals found on the moon’s surface, with simulations backing up the theory. In May, an international research team including the Chinese Academy of Sciences published a paper casting doubt on this hypothesis. A reanalysis found that the central wavelength of the absorption band matched the characteristics of LL chondrites, a type of meteorite with low iron and metal content. The team irradiated LL chondrite meteorite powder with a laser to simulate space weathering caused by solar wind and micrometeorites, and the results closely matched observational data of Kamo’oalewa, suggesting the asteroid migrated to Earth’s vicinity from the Flora family in the asteroid belt.
If Tianwen-2 successfully completes its mission to take samples and return to Earth, it will likely help answer questions about Kamo’oalewa’s origins. But first, it must reach the asteroid’s surface.
The next milestones are the surface landing and sample collection, followed by the release of the sample capsule during the Earth flyby in November 2027.
