science

Tianwen-2

Tianwen-2 is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Tianwen-2 rather than just read about it. In short: Tianwen-2 (Chinese: 天问二号) is a Chinese asteroid sample return and comet exploration mission that launched on 28 May 2025. It is the second mission of the Planetary Exploration of China program of the China National Space Agency (CNSA), and the only planned mission to focus on small Solar System bodies.

Key takeaways

Tianwen-2 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Tianwen-2 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Tianwen-2 from memory before moving on to harder problems.

Reference excerpt

Tianwen-2 (Chinese: 天问二号) is a Chinese asteroid sample return and comet exploration mission that launched on 28 May 2025. It is the second mission of the Planetary Exploration of China program of the China National Space Agency (CNSA), and the only planned mission to focus on small Solar System bodies. The probe departed Xichang Satellite Launch Center on a Long March 3B rocket. On July 4, 2026 the spacecraft arrived at 469219 Kamoʻoalewa, a near-Earth asteroid that is currently a quasi-satellite of Earth. CNSA plans for Tianwen-2 to return samples from the asteroid during an Earth flyby in 2027 by ejecting a capsule into atmospheric entry. After the flyby, the probe is planned to rendezvous with the main-belt comet 311P/PanSTARRS in January 2035, and explore it with its 11 onboard instruments.

Overview CNSA launched the Tianwen-2 probe using a Long March 3B carrier rocket on 28 May 2025 from the Xichang Satellite Launch Center in southwest China. The probe uses solar electric propulsion for maneuvering between its many objectives. It is planned to explore the co-orbital near-Earth asteroid 469219 Kamoʻoalewa and the main-belt comet 311P/PanSTARRS. The spacecraft rendezvoused with Kamoʻoalewa in July 2026 and is conducting remote sensing observations in orbit, while scouting for a sampling site. Tianwen-2 would carry out investigations at progressively lower altitudes from 20 kilometers, 3 km, 600 meters and down to 300 m from the asteroid’s surface before touching down or hovering to collect a sample of regolith. Explosives will be used to expose potential subsurface volatiles for detection. The spacecraft will use both anchor-and-attach and touch-and-go methods to attempt collection of a sample. It would be the first time an anchor-and-attach method has been used on an asteroid, as both OSIRIS-REx and Hayabusa2 used touch-and-go. Tianwen-2 will then return to Earth in 2027 to drop off a return capsule containing the sample and conduct a gravity assist maneuver to propel the spacecraft toward 311P/PanSTARRS. Remote sensing and in-situ measurements will be conducted at 311P/PanSTARRS for at least one year.

History

In 2018, a deep space exploration roadmap covering the 2020–2030 timeframe was proposed by researchers at the Chinese Academy of Sciences, which included an asteroid exploration mission planned for launch around 2022 or 2024. Initially, the space probe was known as ZhengHe, with the name referencing the 15th century Ming Dynasty explorer Zheng He. In spring 2019, after a design study for the mission was carried out by the Chinese Academy of Space Technology (CAST), the CNSA began soliciting international proposals for scientific instruments to be carried on Tianwen-2. In the planning stages, a nano-orbiter and nano-lander were proposed to be deployed to conduct remote sensing and sampling observations. Also, the original secondary target was 133P/Elst–Pizarro, and a flyby of an additional unnamed asteroid may also have been attempted. Tianwen-2 was launched on 28 May 2025 from the Xichang Satellite Launch Center using a Long March 3B launch vehicle and was put directly on an escape trajectory from Earth, a first in the history of this launch vehicle. On 7 June 2026 the spacecraft performed an engine burn to rendezevous with the quasi-moon. Tianwen-2's close encounter with Kamoʻoalewa began on July 4, when the spacecraft approached within 20 kilometers of the asteroid.

Instruments Tianwen-2 will incorporate several types of instruments, including wide/narrow angle multispectral and color cameras, a thermal emission spectrometer, a visible/near-infrared imaging spectrometer, a mass spectrometer, a magnetometer, and a charged/neutral particle and dust analyzer. International contributions to these payloads are being encouraged.

Scientific payload Source:

Visible Infrared Imaging Spectrometer Thermal Radiation Spectrometer Multispectral Camera Medium Field Color Camera Detection Radar Magnetometer Charged and Neutral Particle Analyzers Ejecta Analyzer Narrow Field of View Navigation Sensor Laser Integrated Navigation Sensor

Mission timeline

Illustrations

Worked examples

Example 1 — a first encounter with Tianwen-2

Start with the simplest possible case. Write down what Tianwen-2 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Tianwen-2 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Tianwen-2 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Tianwen-2

In research: Tianwen-2 appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Tianwen-2 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Tianwen-2 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chinese space probes, Earth flybys, May 2025 in China, so understanding it makes those chapters shorter.
In everyday life: Look for Tianwen-2 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Tianwen-2 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tianwen-2 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Tianwen-2 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tianwen-2 in simple terms?

Why does Tianwen-2 matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Tianwen-2?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Tianwen-2.