China Just Sent Back the First Close Up Look at Earth’s Mysterious Quasi-Moon. But the Next Step Is Dangerous

The Tianwen-2 probe reached Kamoʻoalewa, a strange asteroid traveling near Earth.

A Chinese spacecraft has returned the first close-up image of one of Earth’s strangest companions: a tiny, lopsided asteroid that seems to dance beside our planet without truly orbiting it.

The probe, Tianwen-2, has reached Kamoʻoalewa, a rare “quasi-moon” that circles the sun on a path synced with Earth. China hopes to grab pieces of the object and bring them home in 2027—a feat that could reveal whether this small rock was blasted off the moon millions of years ago, as some scientists suspect.

Kamoʻoalewa is a Hawaiian name drawn from the Kumulipo creation chant. It refers to a celestial object that appears to oscillate in the sky.

A Strange Companion

Kamoʻoalewa, also known as asteroid 2016 HO3, belongs to a small class of objects called quasi-satellites. They do not orbit Earth the way the moon does. Instead, they orbit the sun while staying near Earth for long stretches, creating the false impression they are somehow orbiting our planet. Astronomers know of at least seven such objects near Earth. Kamoʻoalewa stands out for spaceflight in particular because it stays close enough for a spacecraft to reach with relatively modest energy expenditure.

Tianwen-2 launched from Xichang Satellite Launch Center on May 28, 2025, aboard a Long March 3B rocket. The China National Space Administration later released an image taken from only about 20 kilometers (12 miles) away from Kamoʻoalewa. The picture shows a small, uneven object that scientists now hope to sample.

Estimates of its size vary. Some reports put it around 16 to 20 meters (50 to 65 feet) wide; others suggest roughly 40 meters (130 feet), still at the low end of previous estimates. Either way, Kamoʻoalewa may rank among the smallest asteroids ever visited by a spacecraft.

Questions to Heaven 2

Tianwen-2 carries 11 scientific instruments and plans to study the asteroid’s shape, composition, and internal structure before trying to collect samples.

But the images beamed back so far, however, suggest the job may be harder than engineers hoped. Kamoʻoalewa is very irregular and may be a rubble-pile asteroid—a loose collection of stones and dust held together by weak gravity. A body that small, fragile, and fast-spinning gives a spacecraft little margin for error.

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CNSA representatives told the South China Morning Post that the terrain “greatly increases the complexity of the sampling process and the risk of the mission, making it much more difficult.”

China has planned multiple sampling options, including contact methods that could work even if the surface proves unstable. The mission’s goal is to return up to about 100 grams of sampled material.

If the attempt succeeds, China would join Japan and the United States as the only nations to return asteroid samples. Japan brought grains from Itokawa to Earth in 2010 and material from Ryugu in 2020. NASA’s OSIRIS-REx mission returned pieces of Bennu in 2023.

Lunar Origin Theory

Kamoʻoalewa draws special interest because it may not have come from the asteroid belt, where many near-Earth asteroids begin their journeys.

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A 2024 Nature Astronomy study proposed that the object could be debris from the moon, possibly launched into space by the impact that formed Giordano Bruno crater. Other studies have explored competing explanations, including origins among rocky asteroid families.

“I am curious to find out the answer about its origin, since the debate on its [potential] lunar origin is still very open,” Marco Fenucci, a mathematician at the European Space Agency’s Near-Earth Object Coordination Centre, told Live Science. “[Returned samples should] definitely give us an answer to this matter.”

Scientists also want to know whether the asteroid contains traces of water-bearing minerals or organic compounds. Asteroids preserve ancient material from the solar system’s formation, making even a spoonful of dust valuable.

Back to Back

Tianwen-2’s mission will not end at Earth.

After releasing its sample capsule during an Earth flyby expected in November 2027, the spacecraft is scheduled to use the planet’s gravity as a slingshot toward 311P/PANSTARRS. That object, located beyond Mars, behaves like both an asteroid and a comet and has displayed multiple dust tails.

Tianwen-2 is expected to reach it in 2035.

The probe’s next challenge is finding a safe way to collect material from a small, dusty asteroid. If it succeeds, the samples could settle whether Kamoʻoalewa came from the moon or from the asteroid belt—and make China the third nation to return pieces of an asteroid to Earth.