科学家首次在月球上发现了一个洞穴。
Scientists have discovered a cave on the Moon for the first time.
他们表示，该洞穴至少有100米深，可能是人类建造永久基地的理想场所。
They say the cave is at least 100 meters deep and could be an ideal location for humans to build a permanent base.
研究人员称，这可能只是隐藏在月球"未被发现的地下世界"里的数百个洞穴中的一个。
Researchers say this could be just one of hundreds of caves hidden in an "undiscovered underground world" on the Moon.
目前，各国都在竞相研究在月球上建立人类永久基地，但他们需要保护宇航员免受辐射、极端温度和太空天气的影响。
Currently, countries are racing to study the establishment of permanent human bases on the Moon, but they need to protect astronauts from radiation, extreme temperatures, and space weather.
英国第一位遨游太空的宇航员海伦·沙曼（Helen Sharman）告诉BBC新闻，这个新发现的洞穴看起来是一个建立基地的好地方，并表示人类有可能在20至30年后就生活在月球坑洞中。
Helen Sharman, the first British person to travel to space, told BBC News that this newly discovered cave looks like a good place to establish a base, and said it's possible that humans could be living in lunar pits within 20 to 30 years.
但她表示，这个洞穴太深了，宇航员可能需要通过绳索下降进入，然后使用"喷气背包或升降机"才能出来。
However, she said the cave is so deep that astronauts might need to descend using ropes and then use "jetpacks or elevators" to get out.
意大利特伦托大学（University of Trento）的洛伦佐·布鲁佐内（Lorenzo Bruzzone）和莱昂纳多·卡雷尔（Leonardo Carrer）利用雷达穿透了月球岩石平原"静海"上的一个坑洞开口，从而发现了这个洞穴。
Lorenzo Bruzzone and Leonardo Carrer from the University of Trento in Italy discovered this cave by using radar to penetrate a pit opening on the Moon's rocky plain known as the "Sea of Tranquility".
这里从地球上肉眼可见，也是1969年"阿波罗11"号（Apollo 11）的着陆地。
This area is visible to the naked eye from Earth and was the landing site for Apollo 11 in 1969.
该洞穴在月球表面有一个洞道，通向垂直的悬壁，以及可能延伸到地下更深处的倾斜层面。
The cave has an opening on the lunar surface that leads to vertical cliffs and possibly sloping planes extending deeper underground.
它是数百万乃至数十亿年前，由熔岩在月表流动时形成的，熔岩在岩石中形成一条条隧道。
It was formed millions or even billions of years ago when lava flowed on the lunar surface, creating tunnels in the rock.
卡雷尔教授解释说，地球上与此最接近的洞穴，应该是西班牙兰萨罗特岛的火山洞穴。他补充说，研究人员参观了这些洞穴以进行研究。
Professor Carrer explained that the closest caves on Earth to this would be the volcanic caves on Lanzarote, Spain. He added that researchers visited these caves for their study.
"这真的令人兴奋。当你有了这些发现并看到这些图像时，你会意识到自己是人类历史上第一个看到它的人。"卡雷尔教授说。
"It's really exciting. When you have these discoveries and see these images, you realize you're the first person in human history to see it," said Professor Carrer.
当布鲁佐内教授和卡雷尔教授了解该洞穴的规模之后，他们意识到这可能是一个建立月球基地的好地方。
When Professors Bruzzone and Carrer understood the scale of the cave, they realized it could be a good place to establish a lunar base.
"毕竟，地球上的生命起源于洞穴，所以人类在月球上住在洞穴里也是合情合理的。"卡雷尔教授说。
"After all, life on Earth originated in caves, so it makes sense for humans to live in caves on the Moon," said Professor Carrer.
这个洞穴还没有被完全探索过，但研究人员希望可以用透地雷达、摄像机甚至机器人来绘制其地图。
This cave has not yet been fully explored, but researchers hope to map it using ground-penetrating radar, cameras, and even robots.
大约50年前，科学家们首次意识到月球上可能存在洞穴。2010年，被称为"月球勘测轨道飞行器"（Lunar Reconnaissance Orbiter）飞船上的一台相机拍摄了一些坑洞的照片，科学家认为这些坑洞可能是洞穴入口。
About 50 years ago, scientists first realized that caves might exist on the Moon. In 2010, a camera on the spacecraft called the Lunar Reconnaissance Orbiter took photos of some pits that scientists thought could be cave entrances.
但研究人员并不知道这些洞穴可能有多深，也不知道它们是否已经坍塌。
But researchers didn't know how deep these caves might be or if they had collapsed.
现在，布鲁佐内和卡雷尔教授的工作已经回答了这个问题，尽管要了解洞穴的整体规模还有很多工作要做。
Now, the work of Professors Bruzzone and Carrer has answered this question, although there's still much work to be done to understand the overall scale of the cave.
"我们有非常清晰的月表图像——分辨率高达25厘米——我们可以看到阿波罗着陆点——但我们对月表以下的情况一无所知。这有巨大的发现机会。"欧洲航天局（European Space Agency）行星洞穴专题小组协调员弗朗西斯科·索罗（Francesco Sauro）告诉BBC新闻。
"We have very clear images of the lunar surface - with resolution up to 25 centimeters - we can see the Apollo landing sites - but we know nothing about what's below the lunar surface. There's a huge opportunity for discovery," Francesco Sauro, coordinator of the European Space Agency's planetary caves team, told BBC News.
他说，这项研究还可能帮助我们将来探索火星上的洞穴。
He said this research could also help us explore caves on Mars in the future.
这可能为我们寻找火星生命的证据打开大门，因为如果生命确实存在，那么几乎肯定它位于免受火星表面自然因素影响的洞穴内。
This could open the door for us to search for evidence of life on Mars, because if life does exist, it's almost certainly located in caves protected from the natural factors on the Martian surface.
月球洞穴可能对人类有用，但科学家们也强调，它可能有助于回答有关月球甚至太阳系历史的基本问题。
While lunar caves might be useful for humans, scientists also emphasize that they could help answer fundamental questions about the history of the Moon and even the solar system.
洞穴内的岩石不会受到太空天气的破坏或侵蚀，因此可以提供数十亿年前的大量地质记录。
The rocks inside the caves would not be damaged or eroded by space weather, so they could provide extensive geological records from billions of years ago.
这项研究发表在科学杂志《自然-天文学》（Nature Astronomy）上。
This research was published in the scientific journal Nature Astronomy.
制图：格里·弗莱彻（Gerry Fletcher）
Graphics: Gerry Fletcher