Study: Better Instruments Needed to Discover Life on Mars

Study: Better Instruments Needed to Discover Life on Mars

A new study suggests that current tools used by scientists to look for signs of life on Mars may not be effective enough to make new discoveries.

A group of international scientists is raising questions about the instruments used on the latest spacecraft and vehicles to explore Mars. The concerns started after researchers carried out tests on soil and rocks in Chile's Atacama Desert. The area is one of the driest places on Earth and one of the oldest deserts in the world.

The area – which is geologically similar to Mars – is often used by scientists to carry out experiments to improve Mars research methods.

The team tested material from a fossil-rich area in the desert called Red Stone. It was once a body of water that now contains a large collection of microorganisms. Such microorganisms, also called microbes, are commonly studied in the search for ancient life on Mars.

The American space agency NASA says this part of the Atacama Desert is dry and rocky and experiences extreme temperatures and severe radiation from the sun. "If you can find life here, you might be able to find it in an even harsher environment – like the surface of Mars," the space agency said in a statement.

Researchers from NASA and other organizations have spent time in the desert testing instruments meant to be used to search for signs of ancient life forms on Mars. Such testing is carried out in areas where bodies of water once existed.

This is because those areas, called deltas², contain higher levels of ancient microbes to study. The Red Stone area was a river delta¹ about 100 million years ago.

In the most recent research, the team tested four instruments at Red Stone that are either currently being used on Mars or are to be used in the future. Research results were recently published in a study in Nature Communications.

The scientists said the instruments were not able to make clear identifications of several "signatures," or signs, that would suggest the presence of "current and ancient microorganisms."

The researchers said the instruments did find "numerous" microbes of unknown classification. Scientists call such microbes "dark microbiome" and they are of limited use in efforts to search for past life on Mars.

The team said their testing led them to believe that the latest instruments used on Mars "might not be sensitive enough" to effectively make discoveries about possible life.

Armando Azua-Bustos was the study's lead writer. He said new instruments and technologies should be considered to improve the current tools used to confirm microbes on Mars.

Azua-Bustos is a research scientist at the Center of Astrobiology in Madrid, Spain. He said ineffective instruments can make confirmed identifications of microbes extremely difficult. The high chance of getting false negatives in the search for life on Mars "highlights the need for more powerful tools," he said.

The team is suggesting that space agencies either put more complex instruments on Mars or bring samples back to Earth for close examination. Such efforts will be needed "to conclusively⁴ address whether life ever existed on Mars," the researchers said.

Both of these plans, however, are extremely difficult to carry out, said Alberto Fairén. He is a visiting scientist in the Department of Astronomy at Cornell University in New York.

Fairén urged planetary researchers to decide which methods are more effective at searching for past life on Mars. The first possibility would be to use the limited abilities and instruments currently on Mars for studying many samples. The other would be to have limited samples examined by the best instruments on Earth designed to identify signs of microbial life.

NASA currently operates two explorers, or rovers, on Mars. One vehicle, Curiosity, is searching an area called Mount Sharp, within the planet's Gale⁵ Crater⁶. Curiosity has been active in the area since landing on Mars in 2012. In addition, NASA's Perseverance⁷ rover has been gathering⁸ rock, soil and atmospheric⁹ samples at Mars' Jezero Crater since September 2021. Both areas are believed to have contained large water bodies in the distant past.

Materials collected by the rovers are expected to be returned to Earth in a future mission. That mission – a joint¹⁰ effort between NASA and the European Space Agency (ESA) – is planned for 2028.

Words in This Story

geology – n. the study of rocks and soil and the physical structure of the Earth

fossil – n. something (such as a leaf, skeleton, or footprint) that is from a plant or animal which lived in ancient times and that you can see in some rocks

harsh – adj. very cold, dangerous or unpleasant and difficult to live in

classify – v. to organize things into groups by their type, size, etc.

negative – adj. a result that does not confirm that something is true

highlight – n. something that draws attention of makes people notice

sample – n. a small amount of something that gives you information about the thing it was taken from

conclusive³ – adj. proving that something is true

address –v. to deal with

mission – n. an important project or trip, especially involving space travel

1 delta   

n.（流的）角洲

参考例句：

• He has been to the delta of the Nile.他曾去过尼罗河三角洲。
• The Nile divides at its mouth and forms a delta.尼罗河在河口分岔，形成了一个三角洲。

2 deltas   

希腊字母表中第四个字母( delta的名词复数 )； （河口的）三角洲

参考例句：

• Tidal channels, deltas, and washover fans are characteristically associated with offshore bars. 潮汐水道、三角洲和冲刷扇典型地与滨外砂洲伴生在一起。
• I know many of the early civilizations prospered on deltas. 我知道很多古老的文明都是在三角洲上蓬勃发展起来的。

3 conclusive   

adj.最后的，结论的；确凿的，消除怀疑的

参考例句：

• They produced some fairly conclusive evidence.他们提供了一些相当确凿的证据。
• Franklin did not believe that the French tests were conclusive.富兰克林不相信这个法国人的实验是结论性的。

4 conclusively   

adv.令人信服地，确凿地

参考例句：

• All this proves conclusively that she couldn't have known the truth. 这一切无可置疑地证明她不可能知道真相。 来自《简明英汉词典》
• From the facts,he was able to determine conclusively that the death was not a suicide. 根据这些事实他断定这起死亡事件并非自杀。 来自《简明英汉词典》

5 gale   

n.大风，强风，一阵闹声（尤指笑声等）

参考例句：

• We got our roof blown off in the gale last night.昨夜的大风把我们的房顶给掀掉了。
• According to the weather forecast,there will be a gale tomorrow.据气象台预报，明天有大风。

6 crater   

n.火山口，弹坑

参考例句：

• With a telescope you can see the huge crater of Ve-suvius.用望远镜你能看到巨大的维苏威火山口。
• They came to the lip of a dead crater.他们来到了一个死火山口。

7 perseverance   

n.坚持不懈，不屈不挠

参考例句：

• It may take some perseverance to find the right people.要找到合适的人也许需要有点锲而不舍的精神。
• Perseverance leads to success.有恒心就能胜利。

8 gathering   

n.集会，聚会，聚集

参考例句：

• He called on Mr. White to speak at the gathering.他请怀特先生在集会上讲话。
• He is on the wing gathering material for his novels.他正忙于为他的小说收集资料。

9 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

10 joint   

adj.联合的，共同的；n.关节，接合处；v.连接，贴合

参考例句：

• I had a bad fall,which put my shoulder out of joint.我重重地摔了一跤，肩膀脫臼了。
• We wrote a letter in joint names.我们联名写了封信。