Chang'e 2
A Moon mapper that went on to make China's first close flyby of an asteroid.
Key facts
- Agency
- China National Space Administration
- Type of mission
- Lunar orbiter and asteroid flyby
- Target
- The Moon, then asteroid 4179 Toutatis
- Launched
- 1 October 2010
- Status
- Completed
Chang'e 2 was built as a backup for China's first Moon orbiter. It was launched in its own right in October 2010, went into a low lunar orbit and mapped the Moon in detail, including the planned landing site of the Chang'e 3 lander.
On to an asteroid
With fuel to spare, it left the Moon in 2011 and flew to the Lagrange point L2, a balance point about 1.5 million kilometres beyond Earth. In 2012 it set off again, and on 13 December 2012 it raced past the near-Earth asteroid 4179 Toutatis at about 10.7 kilometres per second, taking pictures as it went.
Toutatis is an elongated asteroid almost 5 kilometres long, made of two lobes joined together, which tumbles slowly rather than spinning neatly. The images showed boulders and craters, and supported the idea that it is a rubble pile. Toutatis is an S-type asteroid, linked by its colours to ordinary chondrites.
Why it matters to meteorites
Toutatis passes close to Earth every four years. It is a good example of the near-Earth asteroids that deliver most meteorites, and of how these bodies are built of loosely bound pieces. The mission was also China's first step into deep space beyond the Moon, leading to Tianwen-2, its asteroid sample-return mission.
Key dates
| Date | What happened |
|---|---|
| 1 October 2010 | Chang'e 2 launched. |
| June 2011 | Left lunar orbit for the Sun–Earth L2 point. |
| 13 December 2012 | Flew past the asteroid 4179 Toutatis. |
See where this mission fits among all the others in the mission timeline.
Did you know?
Toutatis tumbles rather than spinning around one axis, so its days follow a complicated pattern.
Chang'e 2 was the first spacecraft to visit the Sun–Earth L2 point after leaving the Moon.