![Tianwen-2: Earth's Quasi-Moon Rendezvous](https://cdn.slatesource.com/f/7/8/f7801f2e-ef0f-4560-ad5c-c4ff705ced26.webp) # Tianwen-2: Earth's Quasi-Moon Rendezvous - [Made in Slatesource](https://slatesource.com/@steph/tianwen-2-earth-s-quasi-moon-rendezvous) - By [Steph](https://slatesource.com/@steph) - Created on Aug 5, 2026 **Days** since Tianwen-2 launched toward Earth's quasi-moon ## A quasi-moonquasi-moon with a secretsecret KamoooalewaKamoooalewa (formallyformally 20162016 HO3HO3) is no ordinaryordinary asteroidasteroid. It is 40 to 100100 metresmetres acrossacross, roughlyroughly the sizesize of a citycity blockblock, and it has been loopinglooping aroundaround EarthEarth in a stablestable companioncompanion orbitorbit for at leastleast a centurycentury. AstronomersAstronomers callcall it a quasi-satellitequasi-satellite: not quitequite a moonmoon, not quitequite a passingpassing rockrock, but somethingsomething in betweenbetween. What makesmakes it strangerstranger is its compositioncomposition. SpectralSpectral datadata from the LargeLarge BinocularBinocular TelescopeTelescope in ArizonaArizona foundfound its surfacesurface matchesmatches lunarlunar rocksrocks collectedcollected by the ApolloApollo missionsmissions farfar betterbetter than it matchesmatches any knownknown asteroidasteroid familyfamily. The leadingleading hypothesishypothesis: a long-agolong-ago impactorimpactor hithit the MoonMoon and blastedblasted a chunkchunk into this unusualunusual orbitorbit. On JulyJuly 4 20262026, China'sChina's Tianwen-2Tianwen-2 spacecraftspacecraft flewflew withinwithin 20 km of it for the firstfirst timetime in historyhistory. Spacecraft Tianwen-2 (CNSA) Target Kamoooalewa (2016 HO3) Closest approach July 4 2026, within 20 km Asteroid size 40 to 100 m across Distance from Earth approx 14 million km at flyby Sample return target Earth, late 2031 Second target Comet 311P/PANSTARRS (2034) ![Travel photo 1](https://cdn.slatesource.com/f/7/8/f7801f2e-ef0f-4560-ad5c-c4ff705ced26.webp) ![Travel photo 2](https://cdn.slatesource.com/8/3/8/838cac83-41f7-46ac-96bc-41cc2040c7a8.webp) MOMENT July 4 2026 20 km above Kamoooalewa MOMENT Discovery: April 2016 Haleakala Observatory, Hawaii ## How the samplesample collectioncollection will workwork UnlikeUnlike the flatflat, sandysandy surfacesurface of asteroidasteroid RyuguRyugu where Japan'sJapan's Hayabusa2Hayabusa2 touchedtouched downdown, KamoooalewaKamoooalewa is thoughtthought to be a rubblerubble pilepile of looseloose rockrock with almostalmost no gravitygravity. StandardStandard touch-and-gotouch-and-go samplingsampling wouldwould riskrisk the spacecraftspacecraft driftingdrifting into the asteroidasteroid. ChinaChina is testingtesting a novelnovel anchor-and-attachanchor-and-attach methodmethod: Tianwen-2Tianwen-2 will extendextend a collectorcollector armarm, firefire a tethertether anchoranchor into the surfacesurface, and winchwinch itselfitself closeclose enoughenough to gathergather materialmaterial withoutwithout losinglosing controlcontrol. If it worksworks, it will be the firstfirst timetime this techniquetechnique has been usedused on any smallsmall bodybody in spacespace. The lunar fragment hypothesis is not confirmed. Some planetary scientists argue that Kamoooalewa's spectrum could also match certain volcanic asteroid types. Only a returned sample, analysed in a laboratory, will settle the question definitively. After leaving Kamoooalewa with its samples, Tianwen-2 will not head straight home. The spacecraft is designed for a second act: a rendezvous with the active comet 311P/PANSTARRS in 2034, making it one of very few missions ever to visit two distinct solar system bodies in a single flight. Sample return timeline: Tianwen-2 departs Kamoooalewa orbit approx 2027. A sample capsule re-enters Earth's atmosphere and lands in Inner Mongolia, late 2031. Laboratory analysis begins immediately. If the lunar-fragment hypothesis is confirmed, it will rewrite what we know about how the Moon formed and how material escapes from large bodies. > Kamoooalewa is one of the most scientifically intriguing small bodies we know of. If it really is a piece of the Moon in orbit around Earth, that changes our picture of the inner solar system entirely. [Tianwen-2 Mission Coverage, The Planetary Society](https://www.planetary.org/planetary-radio/2026-tianwen-2?utm_source=slatesource)