2026年4月21日 / 美国东部时间早上7:43 / 哥伦比亚广播公司/法新社
科学家周二表示，美国国家航空航天局（NASA）的“好奇号”火星车在开展一项此前从未在其他行星上进行过的化学实验后，在火星上发现了更多生命构成要素。
由NASA主导的研究团队强调，这些有机分子并非远古生命存在的确凿证据，因为它们也可能是在这颗红色星球上自然形成，或是通过陨石撞击带到火星上的。
但他们补充道，这一发现证明，这些对火星历史具有重要意义的线索已经在火星表面保存了超过30亿年。
人们认为，在30亿年前，火星表面遍布着巨大的湖泊和充满液态水的河流，而液态水是我们所知的生命存在的关键要素。
“随着航天机构派遣火星车和着陆器探索火星过去和现在的宜居性，并寻找生命迹象，对火星上有机物的持续表征是现代机器人探索的支柱之一，”研究作者在周二发表于《自然·通讯》期刊的论文中写道。
“好奇号”于2012年在一个名为盖尔撞击坑的古湖床着陆，此后一直在寻找可能存在的远古生命迹象。
这辆汽车大小的火星车携带了两管名为四甲基氢氧化铵（TMAH）的化学物质，该物质可以分解有机物，以分析其组成成分。
“这项实验此前从未在其他星球上开展过，”参与“好奇号”任务的天体生物学家艾米·威廉姆斯对法新社说道。
描述该研究结果的论文主要作者威廉姆斯补充道，研究团队当时压力很大，因为他们“只有两次机会确保实验成功”。
这项于2020年开展的实验检测到了20多种有机分子，其中包括此前从未在火星上确认存在的数种物质。
美国航天局于2020年11月12日发布的这张照片中，“好奇号”火星车在一个被命名为“玛丽·安宁”的地点自拍，该名称源自19世纪英国古生物学家玛丽·安宁。
这些分子中包括一种名为苯并噻吩的物质，该物质也曾在陨石和小行星中被发现。
“同样从陨石降落到火星的物质也曾降落到地球，这些物质可能为我们地球上已知的生命提供了构成要素，”威廉姆斯说道。
另一种含有氮的分子“是最终构成DNA的前体物质”，她补充道。
“我们目前还不能断言火星上曾存在生命，但我们的发现进一步证明，在地球生命起源的时期，火星曾是一个宜居星球，”威廉姆斯对路透社说道。
未来任务
但所有这些都无法证明，哪怕是微小的微生物也曾在火星上繁衍生息。
威廉姆斯表示，要做出这种“非同寻常的断言”，一种潜在的方法是将一些火星岩石带回地球，以便科学家进行更细致的研究。
美国航天局的“毅力号”火星车已经为这项被称为“火星样本返回”的任务收集了大量岩石。
然而，在今年1月国会投票后，特朗普政府实际上已经取消了这项任务。
去年，“毅力号”在一条干涸的河道中发现了可能包含火星古代微观生命迹象的岩石。
未来的任务仍能从“好奇号”的实验中获益，后者证明了使用TMAH化学物质的实验在其他星球上可行。
欧洲空间局的“罗莎琳德·富兰克林”火星车拥有比“好奇号”更长的钻探装置，将把这种化学物质带到火星上。
经过多年延误，美国航天局上周宣布，欧洲空间局的这台火星车目前定于2028年底发射升空，前往这颗红色星球。
这种化学物质也将搭载在“龙”号旋翼飞行器上，该飞行器计划于2028年发射，任务是探索土星的卫星土卫六。
“好奇号”的最新发现紧随该火星车近期拍摄的一系列照片之后。
去年6月，“好奇号”拍摄了火星某区域的首批特写照片，科学家称这些照片证明了火星上曾经有水流过。从太空看，这些山脊形似蜘蛛网，此前仅通过轨道观测到过这些特征，美国航天局表示。
五个月前，该火星车拍摄了新的照片，展示了火星天空中色彩斑斓的云层。
Mars rover carries out chemistry experiment never done beyond Earth, discovers more building blocks of life
April 21, 2026 / 7:43 AM EDT / CBS/AFP
NASA’s Curiosity rover has discovered more building blocks of life on Mars after carrying out a chemistry experiment never before conducted on another planet, scientists said Tuesday.
The organic molecules are not definitive evidence of past life, the NASA-led team emphasized, because they could also have formed on the red planet or crash-landed on meteorites.
But it proves that these important clues to Martian history have been preserved on the surface for more than 3 billion years, they added.
Back then, the surface of Mars was thought to have been dotted with huge lakes and rivers full of liquid water, a key ingredient for life as we know it.
“The ongoing characterization of organic matter on Mars is a pillar of modern robotic exploration, as space agencies send rovers and landers to explore Mars’ past and present habitability and to search for signs of life,” the authors wrote in the study published on Tuesday in the journal Nature Communications.
Curiosity landed in a former lake bed called the Gale crater in 2012, and has been searching for signs of possible past life since.
The car-sized rover carried two tubes of a chemical called TMAH, which can break apart organic matter to see what it is made out of.
“This experiment’s never been run before on another world,” Amy Williams, an astrobiologist working on the Curiosity mission, told AFP.
The team was under pressure because they only had “two shots to get it right,” added Williams, the lead author of a new study describing the results.
The experiment, conducted in 2020, detected more than 20 organic molecules, including several that had never before been confirmed on Mars.
NASA?s Curiosity Mars rover took this selfie at a location nicknamed “Mary Anning” after a 19th-century English palaeontologist in this image released by the U.S. space agency on Nov 12, 2020. NASA/JPL-Caltech/MSSS
These included a molecule called benzothiophene, which has also been found in meteorites and asteroids.
“The same stuff that rained down on Mars from meteorites is what rained down on Earth, and it probably provided the building blocks for life as we know it on our planet,” Williams said.
Another molecule containing nitrogen “is a precursor to how DNA is eventually built,” she added.
“We cannot yet say that Mars ever harbored life, but our findings further support the evidence that Mars was a habitable world around the time that life on Earth originated,” Williams told Reuters.
Future missions
But none of this can prove that life — even tiny, microbial organisms — once flourished on Mars.
One way to potentially make such an “extraordinary claim” would be to bring some Martian rocks back to Earth so scientists can study them more closely, Williams said.
NASA’s Perseverance rover has already collected a bunch of rocks for such a mission, called Mars Sample Return.
However the mission has effectively been canceled by the administration of President Trump following a vote in Congress in January.
Last year, Perseverance uncovered rocks in a dry river channel that may hold potential signs of ancient microscopic life on Mars.
Future missions could still benefit from Curiosity’s demonstration that experiments using the TMAH chemical work on other worlds.
The European Space Agency’s Rosalind Franklin rover, which has a much longer drill than Curiosity, will take the chemical to Mars.
After years of delays, NASA announced last week the ESA’s rover is now scheduled to blast off toward the red planet in late 2028.
The chemical will also be on board the Dragon rotorcraft, which is planned to launch in 2028 on a mission to explore Saturn’s moon Titan.
The latest discovery by Curiosity follows a series of recent images taken by the rover.
Last June, Curiosity captured the first close-up images of a part of Mars scientists say provide evidence of how water once flowed on the red planet. The ridges look like spiderweb patterns from space and had previously only been observed from orbit, NASA said.
Five months prior, the rover captured new images showing colorful clouds in the sky over Mars.