官方APP下载:英语全能特训(微信小程序版,支持苹果手机、安卓手机)
创办于2003年
UNSV记不住?那就记中文谐音“忧安思危”吧!
  Slow and Steady Wins the Race!
UNSV英语学习频道 - Slow and steady wins the race!
公众微信服务号
英语全能特训(微信公众服务号)
UNSV英语学习频道淘宝网店
客服短信:18913948480
客服邮箱:web@unsv.com
初级VIP会员
全站英语学习资料下载。
¥98元/12个月

Scientists Looking for Life on Mars

阅读次数:


VIP会员专享下载:(非VIP会员无权下载!如果想下载,但还不是VIP会员,请点此订购
下载方式:使用鼠标右键(注意是鼠标右键!)点击下面的MP3音频/MP4视频链接,然后选择“另存为…”。
MP4节目视频 MP4节目视频  MP3节目录音 MP3节目录音 
文章正文
同步字幕
Scientists Looking for Life on Mars
Scientists Looking for Life on Mars

Pictures of the planet Mars show a rocky, lifeless scene. It is hard to imagine plants or animals could ever exist there. But scientists continue to look for evidence.

NASA, America’s space agency, has found evidence that, a long time ago, there was surface water on the Red Planet. Scientists believe water is necessary to support life as we know it. So since that discovery, they have been looking for chemicals that would be present if there once was -- or still is--- life on the planet.

At a December 13 conference in California, NASA scientists reported a breakthrough. They said for the first time that they had found very small amounts of an interesting element. It is called boron.

John Grotzinger is the lead scientist for Curiosity, the space vehicle on Mars that is exploring the planet.

“We have an instrument called the chemistry camera, which has made a detection of boron. And boron is interesting because in some scenarios for the origin of life, boron is able to help catalyze some of the reactions that build materials that could eventually become part of RNA molecules.”

In other words, a camera on Mars showed the element boron. Boron is important because it could help build RNA molecules. And RNA molecules are important because they are one of the essential building blocks for life.

What’s next?

One of the next steps in the scientists’ search for life on Mars comes in 2020. That year, the next spacecraft is scheduled to launch. It will send rocks from Mars back to Earth.

The base of Mars' Mount Sharp is pictured in this August 27, 2012 photo taken by the Curiosity rover (Credit : NASA ) .
The base of Mars' Mount Sharp is pictured in this August 27, 2012 photo taken by the Curiosity rover (Credit : NASA ) .

Scientists in Britain are getting ready for those Mars rocks now. Using a powerful microscope, they have already examined 200-million-year-old volcanic rocks found deep in the Pacific Ocean.

The microscope revealed holes made by tiny living things called microbes. Microbes are the oldest form of life on Earth. They are only the size of one cell.

Peter Cumpson works with Newcastle University.

“What we've been able to do is to look in detail at the carbon chemistry within those tiny structures and identify that as being the remnants of some form of life, probably fungal related.”

Next, the scientists in Britain will examine meteorites formed from ancient material from Mars. The material comes from a time when Mars would have been more likely to sustain life.

Graham Purvis explains what they will be looking for in the material. He is a geoscientist with Newcastle University.

“What we intend to do is have a look at some of the rocks that may be available from NASA, which date back to a time when Mars was much warmer and wetter, and have a look at some of the structures and chemical signatures that we see in those rocks.”

The scientists hope to find tiny microbe holes in the ancient material similar to the ones they saw in the ocean rocks. If they do, they predict that the rocks coming directly from Mars will also show signs of life.

That, in turn, could finally prove that we are not alone.

I’m Anne Ball.

George Putic wrote this story for VOA News. Anne Ball adapted it for Learning English. Kelly Jean Kelly was the editor.

We want to hear from you. Write to us in the Comments Section and visit us on our Facebook page.

Words in This Story

origin – n. the point or place where something begins

catalyze v. to cause an action or process to begin

RNA molecules – n. parts in cells in the body that are building blocks for life and help with genes

remnant – n. the part of something that is left when other parts are gone

fungal – adj. of, relating to or caused by fungus

网友的学习评论(0条):
版权所有©2003-2019 南京通享科技有限公司,保留所有权利。未经书面许可,严禁转载本站内容,违者追究法律责任。 互联网经营ICP证:苏B2-20120186
网站备案:苏ICP备05000269号-1中国工业和信息化部网站备案查询
广播台