Heavenly Questions

The small-body exploration Tianwen-2 is part of China’s interplanetary missions, called the Tianwen series 天问系列. It was preceded by China’s first Mars exploration mission and will be followed by a Mars sample-return mission and a Jupiter system exploration mission. Originally named after the Chinese explorer of the early XV century, ZhengHe 郑和, it was officially renamed Tianwen-2 天问二号 and launched from the Xichang 西昌 space center in Sichuan 四川 on the 29th of May 2025.

The title of the series is a direct reference to a long poem Tianwen 天问, widely translated as Heavenly Questions. It is a lengthy set of open questions attributed to the Chinese poet and political figure Qu Yuan 屈原 of the Warring States period who was slandered and banished for having spoken truth to power over two thousand years ago. Every year, on Duanwujie 端午节,  the 5th day of the 5th lunar year, his death is commemorated. This year, it will fall on the 19th of June, 2026.

The first lines of the poem describe the state of being and not being before the being apprehends itself separately as being. Beyond the hows today’s scientists are tackling, the poem questions why it is the way it is and addresses the order in which things came to be (For a strict interpretation of the text, see Nicholas Morrow Williams, Dialogues in the dark): 

In the first instances of ‘that which feels’, at the origin of origins — the so-called Great Ultimate, who’s there to tell what happened if not through the experience of the state of being and not being? 

When all above and below were not yet formed, how was it built upon and from what vantage point was it observed, felt and investigated? While no direction has yet been chosen, a feeling of being in multiple states coincided with a feeling of not being in any. 

When darkness and light were indistinctly muddled, who could fathom such blurriness and see through it? The random emergence of events set the stage for superposed states of being and not being and, by the same token, the consciousness of being and not being. 

Such an immaterial ethereality, merely a speck of imagination, who was conscious of it? The overflowing chaos was a string of conscious moments in which things moved and communicated. A ripple outward shook the very foundations of such a center of consciousness.

How then did night and day come to be, each owing their own time and space? Time moved forward along with the expansion of space and stretching of distances. Within the boundaries of the universe,  time involved consciousness of time direction.

The exploration of the cosmos fulfills the human mind’s deep-rooted yearning to find its way back home, the cradle that gave birth to star stuff of which humans are made. Tianwen-2 exemplifies the physical outreach of human wanderings, a ripple outward. It is a two-phase mission. Kamo’oalewa is its first target. Its second is an active comet among asteroids of the main belt, 311P/PANSTARRS. The seven year-gap between the time Tianwen-2 will leave Kamo’oalewa to its arrival at 311P/PANSTARRS might provide the opportunity of a fly-by of another asteroid, yet to be determined. 

Initially named 2016 HO3, the asteroid was officially renamed Kamo’oalewa, meaning it is an offspring of unknown origin that travels on its own, a small object that broke off of a larger one, a remnant of something that is not there but of which it was once part. Like Ho’oleilana, the name Kamo’oalewa came from the Kumulipo, referenced in the fourteenth era. It alludes to a celestial object that is oscillating and reflecting the asteroid’s path in the sky when viewed from Earth. 
 

In a state of being or not being, all events are transitory. Even small-body populations, like cosmic superstructures, are transient configurations. Time conceptualizes this transitory process experienced on the human level in the shift from night to day, winter to spring, birth to death, and youth to old age. too. In the mind’s eye, those configurations are like rain bands, each passing on their own schedule, flocks of birds flying in ephemeral murmuration before individual elements escape. 

In small-body populations, asteroids have their physical appearance and life path altered over time. They are celestial bodies made airless by solar winds and cosmic rays. Kamo’oalewa may be a fragment of an unknown parent object — a remnant of a close encounter with Earth-Moon — or an object originated from the main belt. In the swarm of debris and particles escaping from collisions, it survived and settled into an equilibrium state, on the edge of chaos. 

Among near-Earth asteroids, quasi-satellites have laws of motion of their own. A quasi-satellite appears to orbit around the Earth in a rotating reference frame in which the position of the Earth is fixed. In reality, Kamo’oalewa goes around the Sun in almost exactly one year, the time it takes for the Earth to complete its orbital period. Discovered by the Panoramic Survey Telescope and Rapid Response System 1 (Pan-STARRS1) at the Haleakala Observatory in Hawaii on April 27, 2016, it is one of eight quasi-satellites confirmed as of November 2025. 

Periodically switching between a quasi-satellite configuration and a horseshoe configuration, Kamo’oalewa stays outside of the Hill sphere, pulled away on its heliocentric path while still hugging from a distance the Earth and the Moon. Kamo’oalewa’s current quasi-satellite state occurred nearly a century ago. It will transition back to the horseshoe orbit in roughly 300 years at which point the gravitational effect of the Earth–Moon system reaches the weakest point. Jupiter, too, appears to play a major role in the operation of the dynamical mechanism responsible for these transitions. 

Subject to the dynamics of debris transport, Kamo’oalewa wasn’t pulverized nor rapidly accreted by the Earth nor the Moon. Like stars and humans, it too bears the great force of history. It will hang there in its quasi-satellite position for a total of 400 years, considerably longer than the time co-orbital objects usually hold that position on average. Considering the influence of the Earth-Moon system, and the Sun, particularly the impact of space weathering and solar radiation, its very existence and location constitute the epitome of a chance occurrence. 

Notwithstanding the uncertainties around its precise size, shape and density, Kamo’oalewa appears to be a solid, monolithic asteroid, possibly covered by a thin layer of regolith. It has an elongated shape with an estimated size of 69 × 58 × 51 m and a weak surface gravity. While it is a fast rotator — about 28 min, the solar terminator orbit is found to have the best robustness and is suited for global mapping and measurements. The polar region is expected to be the best place for sampling. 

Tianwen-2 will be approaching, and maneuvering carefully, using hovering, touch-and-go and anchoring techniques to collect about one kilo of samples and return the sample capsule to Earth via a flyby in late 2027 before moving on to the second phase of the mission. Kamo’oalewa’s surface morphology, chemical composition, and internal structure will provide more clues as to the evolution of the Earth, Moon and the solar system.  Its formation pathway and dynamical evolution will address — in a more narrowly manner — the broader context of heavenly questions.

The possibility that asteroids with Earth-like orbits have a lunar origin has been raised before. If Kamo’oalewa is a lunar ejecta, soil samples might pinpoint a particular area on the Moon such as the crater Giordano Bruno given the timeline of the formation for, both, the crater and the quasi-satellite. The crater-riddled Moon offers other candidates as well, such as the Tycho crater. Once the exact source is confirmed, it likely will lead to the identification of other objects with the same signature.

The returned soil samples, probably a silicate-based composition, specifically a mixture of olivine and/or pyroxene, will be compared with samples collected in the past by previous missions, including Luna 24 drilling core extracted by a soviet spacecraft that landed on the southeast edge of the Moon’s Mare Crisium in the seventies and Chang’e-5 嫦娥五号 as well as with meteorites, such as those found at the Yamato Mountains in Antartica in the eighties. 

In closing, Qu Yuan’s demise reminds us that, when facing turbulent times, we feel as if we are walking through a spiritual desert. In search of the awakening of the human spirit, we struggle to divert and extract ourselves from the constraints of reality. And so we undertake wanderings into the world of images and ideas. Our spiritual odyssey still bears the burden of our corporeal self. 

While some embrace idols of power and wealth, others turn inwards. Yet, the inner nature can never be detached from worldly matters. Why, the spiritual yearners ask in dismay, the absurd claim that problems and differences among humans can only be resolved through war and violence?

Williams, N. M. (2025). Dialogues in the Dark: Interpreting Heavenly Questions Across Two Millennia. United States: Harvard University, Asia Center.

Demiéville, P. (1973). Choix d'études sinologiques (1921-1970), énigmes taoïstes. Belgium: Brill.

Donald Sturgeon, Chinese Text Project: a dynamic digital library of premodern Chinese, Digital Scholarship in the Humanities 2019, https://ctext.org/chu-ci/tian-wen