VOA慢速：研究表明闪电可能促成地球上生命形成
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A new study suggests lightning strikes that hit Earth after its formation may have unlocked a necessary chemical element to support the beginning of life.
一项新的研究表明在自身形成后撞击地球的闪电袭击可能释放了生命形成所必需的化学物质。
Researchers say the lightning may have supplied enough phosphorus to Earth during the first billion years after the planet was formed.
研究人员表示在地球形成后的十亿年里，闪电可能给地球提供了足量的磷。
Scientists believe life started on Earth about 3.5 to 4.5 billion years ago.
科学家认为地球上的生命起源于约35亿至45亿年前。
Phosphorus is an important element for the formation of life.
磷是形成生命的一种重要成分。
It helps form cell structures and supports DNA, the material present in nearly all living organisms.
它帮助组建细胞结构，并且为DNA提供支撑，DNA是几乎所有活体生物的原料。
But on early Earth, phosphorus is believed to have been locked inside minerals that cannot dissolve in water.
但是人们认为地球形成早期磷存在于不能溶于水的矿物质内。
Until now, it was widely believed that meteorites that struck Earth were mainly responsible for the presence of "bioavailable" phosphorus.
直到现在，人们普遍认为撞击地球的陨石是带来“生物可利用”磷的主因。
Some meteorites contain a phosphorus mineral called schreibersite, a highly reactive mineral that can form organic molecules.
有些陨石含有一种磷元素矿物质叫做陨磷铁矿，它是一种能够组成有机分子的高活性矿物质。
But when lightning strikes the ground,
但是当闪电袭击地球时，
it can create glassy rocks called fulgurites by super-heating and sometimes vaporizing rocks on the surface.
它能通过超高温加热或者有时会汽化地球表面的石头来创造一种叫做闪电熔岩的玻璃质岩石。
This process frees the phosphorus locked inside.
这个过程会释放岩石里面含有的磷。
As a result, these fulgurites can contain schreibersite, which is soluble in water, where life is thought to have formed.
结果就是这些闪电熔岩里会有可溶于水的陨磷铁矿，而水被人们当作是生命的起源。
Researchers in the United States and Britain estimated that early Earth saw 1 to 5 billion lightning strikes hit Earth each year -
美国和英国的研究人员预估地球在形成早期每年会见证10亿到50亿次闪电袭击-
compared to about 560 million yearly today.
与之相比，现在每年大约5亿6000万次。
That would add up to 1 quintillion strikes after a billion years, forming at least 1 billion fulgurites.
十亿年后闪电袭击加起来的次数有百万的三次方次，至少能形成十亿闪电熔岩。
A study describing the research results recently appeared in the publication Nature Communications.
描述这项研究成果的课题近期发表在期刊《自然·通讯》上。
The researchers said phosphorus minerals caused by lightning strikes were found to have been higher by about 3.5 billion years ago.
研究人员表示他们发现闪电袭击产生的磷矿物在大约35亿年前数量更多。
"Lightning strikes, therefore, may have been a significant part of the emergence of life on Earth,"
“因此闪电袭击是地球上出现生命的重要因素，”
said Benjamin Hess, a Yale University graduate student in earth and planetary sciences.
耶鲁大学地球和行星科学专业研究生本杰明·赫斯说道。
He was the lead writer of the study.
他是这项研究的主要作者。
Hess told Reuters news agency that unlike meteorite hits that generally decrease over time,
赫斯告诉路透社，与陨石撞击随着时间逐渐减少不同，
lightning strikes can happen continuously over a planet's history.
闪电袭击可能在一颗行星的历史中持续发生。
He added that this means lightning strikes may also be a very important element for providing the phosphorus needed for the emergence of life on other Earth-like planets.
他补充道，这就意味着闪电袭击可能也是向其他类地行星上提供生命出现所必需磷元素的非常重要来源。
The researchers also examined an unusually large fulgurite formed when lightning struck near a home outside Chicago, Illinois in 2016.
研究人员还研究了2016年伊利诺伊州芝加哥市区外一处住宅发生雷击时形成的一块不同寻常的巨大闪电熔岩。
"Our research shows that the production of bioavailable phosphorus by lightning strikes may have been underestimated,"
“我们的研究表明闪电袭击形成生物可利用磷可能被低估了，”
study co-writer Jason Harvey told Reuters.
该项研究的合作者杰森·哈维向路透社说道。
He is a professor of geochemistry at Britain's University of Leeds.
他是英国利兹大学地质化学专业的教授。
Among the materials considered necessary for life are water, carbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus, along with an energy source.
生命形成必需的原料分别是水、碳、氢、氮、氧、硫和磷，以及能源。
Scientists believe the earliest bacteria-like organisms were formed in Earth's early waters.
科学家认为最早的类细菌形成于早期地球的水中。
But there is a debate over when this happened and whether it happened in warm and shallow waters or in deeper waters.
但是对于形成时间以及到底是形成于温暖的浅水区还是深水区这些问题一直有争论。
Hess said that new research does not completely cancel the theory that meteorites could have been another source of life-giving phosphorus.
赫斯表示新研究并没有完全抛弃陨石可能曾经是形成生命的磷元素的另外一种来源这一理论。
"Meteor impacts around the time of the emergence of life are far less than thought a decade ago," Hess said.
赫斯说：“生命形成时期陨石的影响比我们十年前想象的要小的多。”
"But I don't see our work as a competition against meteorites as a source of phosphorus.
“但是我不认为我们的工作是在反对陨石是磷的来源之一这一理论。
The more sources, the better," he added.
磷的来源越多越好。”他补充道。
I'm Bryan Lynn.
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