VOA科学技术2022 科学家使用模型预测古代火星上生命的生存条件（在线收听）

Scientists Use Model to Predict Conditions for Life on Ancient Mars

科学家使用模型预测古代火星上生命的生存条件

A new study suggests that ancient Mars might have been able to support a large population of microscopic organisms.

一项新的研究表明，古代火星可能已经能够养活大量的微生物。

French scientists used computer models to predict climate and land conditions under the planet's surface about 4 billion years ago.

法国科学家使用计算机模型来预测大约40亿年前火星表面之下的气候和陆地条件。

The study said the microorganisms might have been growing just beneath the Martian surface.

该研究称，这些微生物可能就生长在火星表面之下。

The microbes could have been covered by several centimeters of dirt.

这些微生物可能已经被几厘米厚的尘土所覆盖。

This would have protected them from severe radiation.

这会保护它们免受严重辐射。

The researchers said any place free of ice on Mars could have been filled with the living organisms.

研究人员表示，火星上任何没有冰的地方都可能充满了这些生物体。

But, if they did exist, these simple life forms would have changed the atmosphere so much

但是，如果它们真的存在，这些简单的生命形式会使火星大气层发生很大变化，

that they would not have survived the new environment.

以至于它们无法在新的环境中生存下来。

Boris Sauterey was the lead writer of the study, which recently appeared in the publication Nature Astronomy.

鲍里斯·索特雷是这项研究的主要作者，该研究最近被发表在《自然天文学》期刊上。

He is a postdoctoral researcher at Sorbonne University in Paris.

他是巴黎索邦大学的博士后研究员。

Sauterey said that in the time period studied, Mars was thought to contain lots of water and had less severe conditions than today.

索特雷表示，在该研究所研究的时期，火星被认为含有大量的水，条件并没有现在这么恶劣。

But he told The Associated Press the research results present a picture of how things can develop in the universe.

但他告诉美联社，这些研究结果描绘出宇宙中事物如何发展的图景。

Sauterey said that life on Mars – even simple life like microbes – "might actually commonly cause its own demise."

索特雷说火星上的生命——即使是像微生物这样的简单生命——“实际上可能通常会导致自己的消亡。”

He added that while the findings might seem "a bit gloomy", he also finds them exciting.

他补充说，虽然这些发现可能看起来“有点悲观”，但他也觉得它们令人兴奋。

The researchers said ancient Mars likely had a wet, warm climate.

研究人员说，古代火星可能是温暖潮湿的气候。

But this environment would have been threatened by large amounts of hydrogen being removed from the thin, carbon dioxide-rich atmosphere.

但因为富含二氧化碳的稀薄大气层中大量的氢被这些微生物吸走，这种环境受到了威胁。

Temperatures then dropped by about minus 200 degrees Celsius.

气温随后下降了大约零下200摄氏度。

The researchers said any organisms at or near the surface would likely have buried themselves deeper underground in an attempt to survive.

研究人员说，任何处于地表或接近地表的生物都可能将自己埋在更深的地下以图生存。

This is unlike Earth, where microbes may have helped keep climate conditions more moderate.

这与地球不同，在地球上，微生物可能有助于保持气候条件更加温和。

Researchers say this is because Earth had an atmosphere rich in a nitrogen.

研究人员说这是因为地球的大气层富含氮。

Kaveh Pahlevan is a planetary scientist at the SETI Institute, a nonprofit space research center in California.

卡维·帕列文是芒廷维尤地外理性研究所的一名行星科学家，该研究所是加州的一家非营利性太空研究中心。

He told the AP he thinks any future models of Mars' climate should consider the new French research.

他告诉美联社，他认为未来任何火星气候模型都应该参考法国的这项新研究。

Pahlevan recently led a separate study suggesting Mars was born wet with warm oceans that lasted millions of years.

帕列文最近领导了另一项研究，该研究表明火星诞生时是潮湿的，上面有持续存在了数百万年的温暖海洋。

At the time, the atmosphere would have been dense and mostly hydrogen.

当时火星大气层的密度很大，其中主要是氢。

But over time, some gases were likely transported higher into the atmosphere and lost to space.

但随着时间的推移，一些气体可能到达更高的大气层并消失在太空中。

The French study investigated the climate effects of possible microbes when Mars' atmosphere was mostly carbon dioxide.

法国的这项研究调查了当火星大气层主要为二氧化碳时可能存在的微生物对气候的影响。

So Pahlevan said the research would not relate to earlier times.

因此，帕列文说这项研究不会涉及火星更早的时期。

"What their study makes clear, however, is that if (this) life were present on Mars during this earlier period,

“然而，他们的研究清楚表明，如果（这种）生命在这个较早的时期存在于火星上，

they would have had a major influence on the prevailing climate," Pahlevan said.

它们将对当时的气候产生重大影响，”帕列文说。

The French researchers offered some suggestions about where to look on Mars for signs of past life.

法国这些研究人员就在火星上的何处去寻找过去存在的生命的迹象提出了一些建议。

They named the Hellas Planitia area, as well as around Jezero Crater.

他们命名了“希腊平原”地区，以及耶泽洛陨石坑周围。

Jezero Crater is where the American space agency NASA's exploring vehicle, Perseverance, is carrying out research activities.

耶泽洛陨石坑是美国国家航空航天局的“毅力号”探测器进行研究活动的地方。

Next, Sauterey said he would like to begin research into the possibility that microbial life could still exist deep within Mars.

索特雷说自己接下来想开始研究微生物生命仍存在于火星深处的可能性。

I'm Bryan Lynn.

布莱恩·林恩为您播报。