Facts Worth Sharing
- China's Chang'e-5 spacecraft will return the first Moon samples to Earth since the Soviet Union’s Luna 24 mission in 1976.
- The samples should be the youngest ever returned to Earth: just 1.2 billion years old, when multicellular life may have already evolved on our planet.
- Chang’e-5 will help scientists understand what was happening late in the Moon’s history, as well as how Earth and the solar system evolved.
Why do we need Chang'e-5 ?
The splotches and craters you see on the Moon are scars from the traumatic early days of our solar system. Asteroids and comets slammed into the early Earth and Moon, likely bringing here water that helped life take hold and flourish.
What happened when is still up for debate. Fortunately, scientists can piece together the Moon’s history by studying the age and composition of different lunar regions. While orbiting spacecraft can collect a wealth of valuable data, some scientific experiments can only be done on Earth with instruments that are too large and power-hungry to fly in space. Earth-based experiments can also be repeated in different labs and the samples can be stored for future generations to examine with more advanced technology.
China’s Chang'e-5 mission (嫦娥五号) will return what should be the youngest-ever Moon samples to Earth. The spacecraft will land in Oceanus Procellarum—the Ocean of Storms—a dark-grey region in the Moon’s northwest corner visible with the unaided eye from Earth. The specific landing site, near a 70-kilometer-wide mound named Mons Rümker, may have rocks and soil that are just 1.2 billion years old, formed by a large volcanic event that covered up the underlying surface. That’s far younger than the samples NASA’s Apollo astronauts returned, which ranged between 3.1 and 4.4 billion years old.
By studying samples from rocks that formed relatively late in the Moon’s history, scientists will be able to better understand what was happening on the Moon at a time when multicellular organisms may have already been present on Earth. Knowing the Moon’s history also helps us understand how Earth and the other worlds in our solar system evolved.
How Chang’e-5 works
No spacecraft has returned a sample of the Moon to Earth since the Soviet Union’s Luna 24 mission in 1976. Chang’e-5 will undertake this challenge using an architecture similar to NASA’s Apollo missions. The spacecraft consists of 4 pieces: a service module, a lander, an ascent vehicle, and an Earth return module. In lunar orbit, the lander and ascent module will descend to the surface, while the service module and Earth return module remain in orbit. The lander will collect samples using a mechanical scoop and a drill that can burrow 2 meters underground. Up to 4 kilograms of lunar material will be deposited in the ascent vehicle.
The Chang'e-5 lander also carries 3 scientific payloads. A suite of cameras will document the landing site, a ground-penetrating radar will map the subsurface, and a spectrometer will determine the mineralogical composition of the landing site and calculate how much water is locked in the lunar soil. Scientists will be able to compare these readings with the samples they study back to Earth.
Relying only on solar power, Chang’e-5 will land in the lunar morning and blast the ascent vehicle back into orbit before nightfall—a period of roughly 14 Earth days. The ascent vehicle will rendezvous with the service module and transfer the samples into an Earth-return capsule. The service module will then leave lunar orbit for Earth, releasing the Earth-return capsule shortly before arrival.
Vehicles reentering Earth’s atmosphere from the Moon travel much faster than those returning from low-Earth orbit: about 11 kilometers per second versus 8 kilometers per second. Whereas human-rated vehicles like NASA’s Apollo capsule relied solely on strong heat-shielding, Chang’e-5 will perform a “skip reentry,” bouncing off the atmosphere once to slow down before plummeting to a landing in Inner Mongolia. The landing site is the same used for returning crewed Shenzhou spacecraft.
How you can support Chang’e-5
International space science missions like Chang’e-5 don’t always get the same level of attention as NASA missions. As a space fan, you can share your excitement about Chang’e-5 and encourage others to follow along. You know your audience best; we've got tools to help.
- Find out why missions to the Moon are important
- Stay up to date on Chang’e-5 and other missions by signing up for The Downlink, our weekly newsletter
- Find out how The Planetary Society is working to reduce the cost of sample collection with PlanetVac
Tell the world:
- Spread the Facts Worth Sharing at the top of this article on social media
- Send this page to others using the short URL planetary.org/change-5
- Share pretty pictures of the Moon
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