A Chinese probe to assault two small our bodies of the photo voltaic system | EUROtoday

On May 24, 2025

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C ‘is an appointment with an area pebble like no different that China goals. Around May 28, an extended march 3B rocket will set off from the Xichang area heart, within the southwest of the nation, carrying the Tianwen-2 probe in direction of a unprecedented vacation spot: the Kamoʻoalewa asteroid, quasi-satellite of the earth, which it should carry samples. “” We have by no means visited such a small object which turns so shortly on itself, ”underlines Patrick Michel, CNRS analysis director on the Côte d’Azur Observatory and a world asteroid specialist. In reality, this area rock 40 to 100 meters in diameter, which escorts our planet in its orbit across the solar, performs an entire rotation on itself each 28 minutes.

“A real headache for engineers! »Points Patrick Michel. “” Evolving around a body that is a few tens of meters in diameter is complicated. To put yourself in orbit, you really have to get close very close and even if you just follow it, the maneuvers remain very sensitive, because there is really very little gravity and its rapid rotation does not forgive any error. »»

If approaching the asteroid is already a feat, taking samples in it is a still superior complexity. No doubt to put the odds on their side, Chinese engineers have planned two sampling methods. First, a classic approach called “Touch-And-Go”, already tested by Americans and Japanese: the probe will touch the surface to suck a few grams of dust. But they also developed a second more daring method: four robotic arms equipped with drilling to anchor directly in the rock. Objective: to collect at least 100 grams of samples.

To carry out this mission, Tianwen-2 has an arsenal of eleven complementary scientific instruments. The probe is equipped with several types of cameras (multispectral, hyperspectral and navigation) and different spectrometers which will analyze in detail the composition and surface of Kamoʻoalewa. A particle detector, developed in collaboration with Russia, will study the spatial environment around the asteroid, while a dust detector will measure the particles of material ejected from its surface. A low frequency radar will probe the internal structure of the asteroid, a first for an object of this size.

A missing link

Why so much effort for such a small body? “All asteroids are interesting. As proof, so far, each of those we have visited has surprised us, without exception, ”recollects Patrick Michel. Kamoʻoalewa, nonetheless, aroused explicit curiosity for 2 causes. First, by no means an object so small and turning so shortly on itself has been approached and sampled. “What is a pebble that has so little gravity and that turns so quickly on itself?” Is it a monolithic rock or an agglomerate with minimal cohesion? The scientist wonders. A query that strongly resonates in planetary protection: Kamoʻoalewa is certainly of measurement similar to the thing which devastated Toungouska in Siberia in 1908.

Even extra intriguing, this asteroid may very well be a fraction of the moon, torn off throughout an influence. A speculation that Patrick Michel and his colleagues supported in an article revealed in Nature Astronomy In April 2024. “If it’s a lunar ejecta, we are able to perceive how the fabric is reworked in the course of the impacts. Is it melted? What state is it in? »Underlines the scientist. His examine would make it attainable to fill an essential hole in our understanding of influence physics.

Indeed, if scientists know small lunar meteorites effectively and might mannequin giant impacts, intermediate -size objects like Kamoʻoalewa stay mysterious. The researchers even recognized its attainable homeland: the Giordano Bruno crater, a construction of twenty-two kilometers in diameter shaped lower than 10 million years in the past. If this speculation is confirmed, the evaluation of the samples would enable for the primary time to check the ejected matter by straight connecting it to its supply crater.

Mysterious exercise

But the ambition of Tianwen-2 doesn’t cease there. Once the Kamoʻoalewa samples dropped to the earth in 2027-2028, the probe will use the gravitational help of our planet to start out in direction of its second goal. A seven -year journey awaits him to hitch the 311p/Panstarrs comet, situated in the principle asteroid belt between Mars and Jupiter. “It is an object that has an activity, which emits dust,” explains Patrick Michel. This exercise, the origin of which stays mysterious, may very well be due both to direct impacts, or to the discharge of unstable components within the sub-surface throughout these impacts, creating pockets of stress that eject materials.

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The kangaroo of the day

Answer

It would be the first time {that a} comet of the principle belt will likely be noticed carefully. These objects significantly intrigue scientists, as a result of they may not prepare of their present location: like all comets wealthy in unstable components, they needed to be transported from the exterior areas of the photo voltaic system throughout giant planetary migrations.

This double mission is a part of a brand new period of exploration of the small our bodies of the photo voltaic system. “All the knowledge that we currently acquire will feed both basic research and planetary defense and exploitation of space resources,” underlines Patrick Michel. A strategic difficulty effectively understood by Beijing: with Tianwen-2, China joins Japan and the United States within the very closed circle of countries able to bringing asteroid samples, whereas Europe, regardless of the success of missions like Rosetta, stays exterior this elite. After Tianwen-1 on Mars, this ten-year mission marks an extra step within the Chinese ambition to unravel the secrets and techniques of the photo voltaic system itself.

https://www.lepoint.fr/astronomie/une-sonde-chinoise-a-l-assaut-de-deux-petits-corps-du-systeme-solaire-23-05-2025-2590389_1925.php