Kamo\u2019oalewa was visited by a Chinese probe, Tianwen 2. The latter\u2019s name refers to the broader solar system exploration program, Tianwen 1, launched towards Mars in 2020 and a spectacular success. It was the first time an orbiter, a lander, and a rover were sent on the same spacecraft. All three functioned perfectly on the first attempt. The Chinese space agency also included several automatic cameras to photograph both the spacecraft orbiting Mars and the rover and lander on the surface in a famous \u201cselfie\u201d that went viral around the world.<\/p>\n
Tianwen 2 is an asteroid exploration and sample-return spacecraft. Its target was a small rock orbiting close to Earth \u2014 so close, in fact, that it is considered one of our quasi-satellites. Since it was discovered by a telescope located in Hawaii, Kamo\u2019oalewa was given a Hawaiian name, a reference to a line from a traditional Hawaiian song.<\/p>\n
Tianwen 2\u2019s journey took only 400 days \u2014 very short compared to the typical duration of similar missions. This is because Kamo\u2019oalewa follows an orbit around the Sun very similar to that of Earth, and it has nearly the same orbital period: about 365 days. That\u2019s why it never strays very far from us.<\/p>\n
To get to it, the spacecraft used an ion engine with a very low thrust, but that is capable of operating for days on end. Rendezvous and orbital insertion maneuvers are performed using chemical thrusters, which are much more powerful.<\/p>\n
Before launch, Kamo\u2019oalewa was thought to be about 100 meters in size. But photos transmitted by Tianwen 2 show that it is much smaller, just shy of 99 feet, side to side. Since with its solar panels extended, the spacecraft has a wingspan of 39 feet, once it lands on the surface, it will cover almost half the asteroid. Its relative size recalls the baobab shoots the Little Prince must uproot each day to keep them from destroying his Asteroid B-612.<\/p>\n
On such a small mass, gravity is practically non-existent. This makes it a very tricky place to land. The European probe Philae attempted to do so on the Churyumov-Gerasimenko comet<\/a>. Though it was equipped with harpoons and drills to affix itself to the ground, its attempts didn\u2019t work, with the vehicle bouncing when it tried to fall into a fissure on the meteor\u2019s surface.<\/p>\n After learning from that experience, the Chinese vessel was equipped with more docking systems: four flexible feet to reduce impact on the ground, and tiny \u201cclaws\u201d on its contact pads designed to grip small cracks in the regolith. In addition, the base of the pads is covered with a synthetic material that \u201csticks\u201d to the ground, much like the feet of lizards that allow them to climb vertical walls.<\/p>\n To collect samples, Tianwen 2 will make use of drills mounted on its legs. They are not traditional motor-driven drill bits. Not only are they very heavy, but when they bite into the ground, they cause the entire spacecraft to be propelled upward by simple reaction. Plus, regolith dust could clog the drill bit\u2019s flutes.<\/p>\n Chinese engineers have opted for ultrasonic drills on the country\u2019s ship. These consist of a rod that rests gently on the ground, thereby preventing the rebound effect. Through this rod, piezoelectric crystals transmit high-frequency vibrations powerful enough to pulverize rock in a process similar to that of the lithotripsy equipment used to treat certain kinds of kidney stones.<\/p>\n With this system, Chinese technicians hope to collect around 100 grams of samples and bring them back to Earth. That\u2019s more or less the same quantity obtained by NASA from the Bennu asteroid in 2023<\/a>, and much more than Japan collected on its two previous missions in 2005 and 2018, during which it came back with less than a milligram on the first attempt and a modest five grams on the second.<\/p>\n When will it happen? All operations in low-gravity environments are extremely critical. Any mistake could send the spacecraft back out into space. For now, Tianwen 2 is in an orbit nearly 19 miles from the asteroid\u2019s surface, where it has been taking the first of its photos. Over the next few weeks, it will gradually descend, first to an altitude of two miles, then to just shy of 1,000 feet, where it will identify its most suitable landing sites.<\/p>\n Its final approach and sample collection will take place in early 2027. Once this is done in April, it will fire its chemical engines to break out of orbit around the asteroid and return to Earth\u2019s vicinity to release the capsule containing its collected material. It will then use Earth\u2019s gravitational pull to accelerate toward its next and most distant target: Comet PanSTARRS, which it is scheduled to encounter in January 2035.<\/p>\n China announced the success of its visit to Kamo\u2019oalewa on July 5. The following day, Japan\u2019s space agency, JAXA, released a similar announcement. Its Hayabusa 2 spacecraft, a veteran probe with more than 12 years under its belt, had just visited another asteroid that had never been seen up close. It was so unknown it didn\u2019t even have a name, just a number: 98943.<\/p>\n At the beginning of 2023, JAXA convened a public vote on the best name for the asteroid. From 3,000 proposals, a jury of nine children selected \u201cTorifune,\u201d from a mythological boat that was \u201cfast as a bird and solid as a rock.\u201d<\/p>\n And my, was it fast. The probe passed by it like a streak of lightning, at a relative speed of 11,000 miles per hour. It was also as solid as its namesake. The flyby took place 2,600 feet from the center of the asteroid \u2014 that is, just 980 feet from its surface. Never before had such a close encounter been carried out.<\/p>\n In the few seconds that the final maneuver lasted, the cameras had just enough time to take a photo of the asteroid. Cue the surprise: Torifune is peanut-shaped, almost a twin of Itokawa, the target asteroid of the first Hayabusa probe in 2005.<\/p>\n Both Itokawa and Torifune are masses of debris consolidated into a single body by their own gravity. They are likely fragments produced by an impact that occurred 4.5 billion years ago, during the formation of the solar system. They are what is referred to as \u201ccontact asteroids.\u201d<\/p>\n While the material from which they are made originated from a violent collision, their formation millennia later was a much gentler process. Their two lobes, created by the accumulation of debris, gradually drew closer together through pure gravitational attraction. They began to orbit one another, until tidal forces and the loss of orbital energy gradually brought them together, and they made contact. They are held together by their extremely weak gravity and the friction of their materials.<\/p>\n Contact asteroids appear to be more common than previously thought. In addition to Itokawa and Torifune, Comet Churyumov-Gerasimenko \u2014 which was visited by the European Rosetta probe<\/a> \u2014 is also a contact asteroid, possessing two nearly spherical protrusions that make it resemble (depending on one\u2019s viewpoint) a rubber duck. That shape is similar to that of Arrokoth, the most distant object that has been observed to date, located beyond Pluto. It was photographed by the New Horizons spacecraft<\/a> in 2019.<\/p>\n At any rate, no matter how common their morphology, it is surprising that Itokawa and Torifune appear almost identical in both shape and size (about 500 meters in length). It is difficult to tell one from the other, though this may be due to the angle at which its image was captured.<\/p>\n The goal was not merely to set a speed record in approaching Torifune. Almost the entire approach was carried out using autonomous guidance. Onboard cameras first detected it as a faint point of light several weeks ago, and the spacecraft\u2019s thrusters adjusted its trajectory with exacting precision.<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/07\/TN75T47XPJEIPLMNJ4AP3CSJEU.jpg\")
An illustration provided by NASA depicts the OSIRIS-REx spacecraft at the asteroid Bennu.AP<\/p>\n