这份从月球打包回来的“土特产”，有何特别之处？

升空、落月、采样、交会对接……

嫦娥五号已完成一系列“复杂高难度动作”

踏上归家之途

和它一起回来的

还有来自月球的“土特产”

约两公斤左右月球岩石和土壤样品

这份“土特产”来自月球哪里？

有何特别之处？

返回地球后如何存放？

一起来看

China's Chang'e-5 probe is on its way back to Earth, bringing with it about 2 kilograms of soil and rocks from the moon, which will be the first fresh lunar sample obtained by humanity since 1976.

If everything goes smoothly, the sample is expected to land on the grasslands of Inner Mongolia by mid-December, according to the China National Space Administration (CNSA).

Here is what we know so far about the sample, which could prove key to unlocking many mysteries about the moon.

“土特产”来自哪里？

Where were the samples taken from?

此次嫦娥五号着陆的区域位于月球正面风暴洋中的吕姆克山。

吕姆克山以德国天文家吕姆克（Carl L. C. Rümker）的名字命名，位于风暴洋北部，底部直径70千米。这是此前人类从未 探索 过的区域。

为了提高采样的可靠性，增加样品的多样性，嫦娥五号在吕姆克山取样时采用了 “钻取”和“表取”两种方式。

“表取”，顾名思义就是从月球表面通过机械臂和机械爪的配合，抓取一部分月球样品；而“钻取”则是要通过特殊的钻头，钻到月表以下两米左右的位置，把月球样品整体取出来。

The landing site of Chang'e-5 was Mons Rümker, a 70-kilometer-wide volcanic mound in the region known as Oceanus Procellarum (Latin for "Ocean of Storms") on the moon's near side – the vast, dark lava plains visible from Earth with the naked eye.

It's a place untouched by humanity.

The lander shoveled up some surface material and also drilled a 2-meter-deep hole and scooped up soil and rock from inside it.

The landing sites of Chang'e-5 and previous lunar landing missions by the U.S. /NASA

为什么选择这里的“土特产”？

Why collect samples from Mons Rümker?

上世纪六七十年代，美国开展了6次登月任务，先后带回了约382千克月球岩石和土壤样品；前苏联的月球探测器进行了3次月球采样，共采集到约300克样品。

美国和前苏联采集的月球样品大多形成于30亿至40亿年前。科学家对这些月球样品研究后发现，月球上的火山活动在35亿年前达到顶峰，然后减弱并停止。

In the late 1960s and 1970s, the United States brought back to Earth 382 kilograms of lunar material from six moon-landing missions, while the former Soviet Union retrieved about 300 grams over three missions.

All those samples are very old – 3 to 4 billion years in age. Analysis of the samples suggests that volcanic activity on the moon peaked 3.5 billion years ago, then faded away and stopped.

但通过观测月球表面的其他特征，科学家发现月球某些区域可能含有地质年龄较短的火山熔岩，这又说明月球上的火山活动可能停止得相对较晚。

嫦娥五号着陆的吕姆克山附近，就可能存在形成于13亿年前的玄武岩，这在月球表面属于“非常年轻”的玄武岩。对这些岩石进行采样并研究其形成时间，可以确认该区域火山活动的起始时间，为科学家研究月球火山活动和月球演化 历史 提供线索。

But Mons Rümker, where Chang'e-5 collected its sample, may have erupted as recently as about 1.3 billion years ago and contain "the youngest mare basalt on the moon," according to scientists.

Such "young" rocks from the moon have never yet been sampled or studied.

If Chang'e-5's samples confirm that the moon was still active during this time, it could fill an important gap in scientists' understanding of the moon's volcanic activity, and rewrite the history of the moon.

Studying the rocks' composition could also clarify what fueled this thermal activity for so long.

"The landing site was extremely wisely picked," Harald Hiesinger, a geologist at the University of Münster in Germany, told Nature.

Brett Denevi, a planetary geologist at Johns Hopkins University in the U.S. and science chair of a NASA lunar analysis group, said China picked a spot where it could have a big scientific impact.

"Understanding the age of those samples and all of the Solar System–wide implications that flow from that result will be a big leap forward for planetary science," she was quoted as saying in Science magazine.

The landing sites of Chang'e-5 and previous spacecraft from the U.S. and Russia. /CNSA

归来后“土特产”如何存放？

How will the samples be handled?

中国科学院国家天文台已建成国内首个月球样品实验室，以便妥善处理和研究这份来自月球的珍贵“土特产”。

月球样品返回地球后，将存放在密封装置中，然后转移至实验室。实验室有专门的设备防止样品被地球上的大气和水污染。研究人员在经过解封、分样和存储等步骤后，会对样品进行长期研究，包括分析样品的矿物质和化学组成等。

除了用于科学研究，还有一部分样品会向公众进行展示。

In order to properly handle and study this precious material, China has built a lunar sample laboratory at the National Astronomical Observatory (NAO) under the Chinese Academy of Sciences in Beijing, dedicated to its storage, processing and analysis.

Once it has landed on Earth, the sample will be transferred to the lab in a sealed container. The lab has a special facility that will prevent the sample from being contaminated by the atmosphere and water on Earth.

Scientists at the lab will first unpack, sort out and store the material. They will then conduct long-term studies of the sample as per strict and scientific experiment design, including analyzing its mineralogical and chemical makeup.

Some of the sample will also be set aside for public display, according to Li Chunlai, deputy chief designer of the Chang'e-5 mission.