「媒库文选」从前，在火星上

参考消息网3月22日报道
Once Upon a Time on Mars
从前，在火星上
Dennies Overbye 丹尼斯·奥弗比
hree and a half billion years ago， waves splashed and streams surged across this dusty expanse on Mars now known as Jezero Crater. On a nascent Earth， chemistry was coagulating toward the exalted state we call life.
Astronomers， philosophers and science fiction writers have long wondered whether nature ran the same experiment there as on Earth. Was Mars another test tube for Darwinian evolution？
So humans have sent their progeny across time and 300 million miles of space in search of long-lost relatives， ancient roots of a family tree that might be traced in the Red Planet"s soil.
The Perseverance rover and its little sibling， the Ingenuity helicopter， landed in a cloud of grit on Feb. 18， bristling with antennas and cameras. Perseverance will spend the next Martian year — the equivalent of two Earth years — prowling， poking and collecting rocks from Jezero Crater and the river delta that enters it. The rover will scrutinize the debris chemically and geologically， and take photographs， so that scientists on Earth can search for any signs of ancient fossilization or other patterns that living organisms might have produced.
Perseverance and Ingenuity operate on very long leashes: 12 minutes of light-travel time — and signal delay — across the ether from Pasadena， where their creators and tenders wait to see what they have accomplished lately. Like the teenagers you let out the door with the car keys， Perseverance and Ingenuity are no more intelligent and responsible than humans have trained them to be.
Those rocks will be picked up and returned to Earth in a five-year series of maneuvers involving relay rockets， rovers and orbital transfers starting in 2026 that will make the retrieval of the moon rocks look as easy as shipping holiday cookies to your relatives. The rocks that return starting in 2031 will be scrutinized for years， like the Dead Sea Scrolls， for what they might say about the hidden history of our lost twin and，perhaps， the earliest days of life in the Solar System.
The generation that followed World War II carried out the first great reconnaissance of the solar system. It could be the destiny of this generation to carry out the next great reconnaissance， to discover if we have or ever had any neighbors on these worlds. In Jezero Crater，the dream lives on. We may not ever live on Mars， but our machines already do.
在火星上，有一个尘土飞扬的广袤区域今天被称作“耶泽罗陨石坑”。35亿年前，那里曾波光粼粼，溪流淙淙。而在初生的地球上，化学元素正朝着我们称之为“生命”的活跃状态凝结。
长久以来，天文学家、哲学家和科幻小说家一直在思索，大自然是否也在火星上进行了与在地球上同样的实验。火星是达尔文进化论的另一个试管吗？
所以，人类让子孙后代穿越时间和3亿英里的空间寻找失散已久的亲人——也许可以追溯到那颗红色星球土地上的家族谱系的古老根源。
今年2月18日，“毅力”号火星车和它的小兄弟“机智”号直升机搭载天线和摄像机，在一团尘埃中登陆火星。未来的一个火星年——相当于地球上的两年，“毅力”号将在耶泽罗陨石坑和汇入其中的三角洲地区搜寻、钻探并收集岩石。“毅力”号将从化学和地质学的角度仔细察看这些岩石的碎屑并进行拍照，这样地球上的科学家就能寻找远古石化或生命体可能产生的其他形态的迹象。
“毅力”号和“机智”号有很大的行动自由：与帕萨迪纳市（它们的创造者和操控者正在那里期盼看到它们最近的收获）隔着光直线传播12分钟的距离，还有信号延迟。就像你允许拿着汽车钥匙出门的青少年，“毅力”号和“机智”号的聪明与责任感仅限于人类给予的训练。
从2026年开始，历时5年，这些岩石将通过一系列涉及转运火箭、火星车和变轨的操作被取走并运回地球。与之相比，回收月球岩石如同给亲人寄送节日饼干一样容易。从2031年开始回收的岩石将被仔细研究多年，就像研究死海古卷一样，它们也许会揭示我们失散的孪生同胞（也许还有太阳系诞生之初生命）的隐秘历史。
二战后的那一代人完成了对太阳系的第一次伟大探索。这一代人也许注定要完成下一次伟大探索，去发现我们在这些世界里是否有或曾有过邻居。在耶泽罗陨石坑，这个梦想仍在继续。也许我们永远无法在火星上生活，但我们的机器已经做到了。（刘白云译自3月2日美国《纽约时报》网站）