Chang'e-6 has just returned, and China's next extraterrestrial exploration and sampling plan has been decided.
The launch time is around 2025, but this time the place to go is a little interesting, a "small moon" around the earth.
Some friends may say, isn't there only one satellite on Earth? Where did the little moon come from?
In fact, the place where Tianwen-2 will go to dig next year is an asteroid orbiting the earth.
Because it will still "never leave" the earth for hundreds of years to come, it will be called the "little moon".
So what is the research value of asteroids? Why is China digging for asteroids?
Let's find out!
1. The launch time of Tianwen-2 has been set
In July 2020, the mainland successfully launched the Tianwen-1 Mars probe.
Now, four years later, although "Zhurong" has fallen asleep on Mars, "Tianwen-1" is still orbiting Mars, accumulating savings for scientific exploration missions.
Unlike the "Chang'e" series of probes, the target is the moon, but the target of the "Tianwen" series of probes is not just Mars.
Because the mainland has now announced the timetable for the Tianwen-2 mission, as well as the follow-up Tianwen-3 and Tianwen-4, they are not going to the same place.
Tianwen-2, for example, will launch in May 2025 to a near-Earth asteroid.
Tianwen-3 and Tianwen-4 will be launched around 2030, one to complete the return of Martian samples, and the other to explore the Jupiter system.
So what's so special about the asteroid that Tianwen-2 is going to?
2. Tianwen-2 is going to dig the "little moon"
The asteroid that Tianwen-2 is going to dig is the "2016HO3" asteroid discovered in 2016.
In the past 100 years, it has been one of the most stable near-Earth objects near the earth, and it will continue to be so for hundreds of years afterward, so although the earth only has a moon of the moon, it can be regarded as a "quasi-satellite" of the earth, and before it leaves the earth, finding a window to explore it will also provide relevant clues for human exploration of the universe and solving some mysteries of the solar system.
Through the previous study of "2016HO3", many astronomers believe that it may be a part of the earth, and that it finally entered the orbit around the sun after a certain moon impact.
Because from the spectral analysis, it has a lot of similarities with the moon, and its orbital energy is also very close to the Earth-Moon orbital energy, of course, these are just speculations, whether "2016HO3" is from the moon, it needs to be through follow-up sampling research on it, to find the answer.
Before the launch of Tianwen-2, the mainland had successfully taken samples from the front of the moon and the back side of the moon and brought them back to the earth, so after sampling from "2016HO3" next year, we can figure out what kind of connection it has with the moon through comparison.
Like Chang'e-6, next year's Tianwen-2 will also be an international cooperation project.
When designing the Tianwen-2 probe, the mainland has reserved a 200-kilogram carrying capacity, which can carry the payload of cooperative countries or scientific research institutions, and as long as the cooperation plan they apply for is approved, then it can be carried and shared for free.
Of course, some of the expenses incurred during the period need to be borne by yourself.
If next year's Tianwen-2 mission is successfully completed, the continent will also become the third country to return samples from asteroids.
The first two countries that have completed asteroid exploration and sampling are Japan and the United States.
Looking at the global aerospace field, although Japan gives people the feeling of average strength, but in terms of asteroid exploration, Japan is the first country to achieve results, which may also be because Japan knows that its strength is not strong enough, so when all countries are focused on the moon and Mars, he chooses to explore asteroids.
As early as 2010, Japan successfully returned samples from the asteroid "Itokawa", and through the study of the retrieved samples, Japanese researchers found that the mineral components on it are common on Earth, the Moon and Mars.
Therefore, there were also suspicions at the time that the asteroid samples retrieved by Japan had actually been contaminated by materials on the earth's surface or cosmic dust.
In September 2016, NASA launched the "Osiris-REx" probe, and after seven years, it finally completed sampling the asteroid "Bennu" in September 2023.
However, NASA has not yet released the relevant research status.
Therefore, after Chang'e-6 returns, some netizens think that if NASA wants a lunar soil sample from Chang'e-6, it can exchange the sample of "Bennu".
However, in fact, this exchange is of little significance, and our Chang'e-6 sample itself is more valuable than that of "Bennu", not to mention that we will go to the asteroid to sample next year, so we are still looking forward to our "Tianwen-2", what do you think about this?