This is the first-ever close-up view of one of Earth’s (known) eight “Mini-Moons” — or quasi-satellites as NASA calls them. So-called because they orbit both Sun and Earth simultaneously, never straying far from Earth. The scale bar “10米” translates to “10 meters.” The 米 symbol is used here because the image was captured and released by the China National Space Administration (CNSA) from their Tianwen-2 mission. The rock is about 66 feet in diameter (about the size of a school bus) and it rotates on its axis every 28 minutes. The image was captured on July 2, 2026, from a distance of around 20 kilometers.
The object, officially known as 2016 HO3, was first discovered by the Haleakala Observatory in Hawaii on April 27, 2016. It’s also known as Kamoʻoalewa, a Hawaiian word meaning “wobbling celestial object.” Astronomers calculate that it’s been orbiting Earth since the 1920s, and will likely stick around for another few centuries. These quasi-moons come and go, sometimes hanging out for only a couple years, sometimes for centuries. Their orbits are unstable in the long term, since they are perturbed by the gravity of the Sun, Earth, and (real) Moon.
It’s difficult to imagine an object orbiting both the Sun and Earth simultaneously, so NASA’s Jet Propulsion Laboratory (JPL) has produced an excellent animation of 2016 HO3‘s motion. Here they show what happens from an Earth-based perspective. Of course, both Earth and 2016 HO3 orbit the Sun with a period of approximately 365.25 days, which is the time it takes for 2016 HO3 to complete one orbit of Earth:
2016 HO3 loops around Earth, coming as close as 9 million miles and as far as 25 million miles from our planet. So it’s well beyond the orbit of the Moon (239,000 miles) and not at all a collision threat. Interestingly, there is some evidence that 2016 HO3 may actually be a piece of the Moon blasted off by an asteroid impact in the distant past. Tianwen-2 might just be able to confirm or refute that hypothesis.
Tianwen-2’s equipment will allow it to recover samples in three ways, depending on the situation. One way uses a touch-and-go method similar to that used by NASA’s OSIRIS-REx asteroid sampling mission and Japan’s Hayabusa2 asteroid mission. Tianwen-2 may also attempt an anchor-and-attach method, which involves the spacecraft physically attaching itself to the space rock and then collecting samples of the surface and subsurface. It could also use a hovering method, whereby a robotic arm will deploy from the spacecraft as it hovers above the asteroid and scoop up some of the surface material.
Tianwen-2 will return those samples on its next pass by Earth, after which it is set to continue its journey to comet 311P/PanSTARRS, where it will conduct further observations and scientific studies. Samples will be dropped in a reentry capsule that deploys parachutes enabling a soft landing in the Gobi Desert. Laboratory analysis will be able to compare isotopic ratios found in existing Moon rocks to those in the samples.
It will be interesting to learn more about 2016 HO3 and its origins. All Earth’s quasi-moons might be ejected lunar material, or some might be captured asteroids. Only future in situ analyses will tell.
Next Week in Sky Lights ⇒ When Optics Meets Electricity