VOA科学技术2024--Mars Explorer Arrives at New Area in Search for Evidence of Water, Life

Mars Explorer Arrives at New Area in Search for Evidence of Water, Life

　　The American space agency's Mars explorer, Curiosity, has reached a new area of the planet Mars as it searches for evidence of water and possible life.

　　The explorer, or rover, recently arrived at an area called the Gediz Vallis Channel. Researchers said the area was chosen because evidence suggested that it once held large amounts of liquid water. The term "channel" describes a natural bed that carries water.

　　Curiosity arrived on Mars in 2012 and began exploring areas around the planet's huge Gale¹ Crater². Mars is a cold, dry desert today. But the Gale Crater area is believed to have contained a lake at one time and has shown other evidence of flowing water in the past.

　　A large meteor strike about 3.7 billion years ago is believed to have formed the crater. At the time, scientists believe groundwater filled Gale Crater while additional water flowed in from rivers fed by rain or melting snow. This is thought to have formed Gale Crater's large lake.

　　Since 2014, Curiosity has been exploring an area called Mount Sharp, which sits about five kilometers above the floor of Gale Crater. NASA said the new area contains formations created "over millions of years amid a changing Martian climate."

　　Curiosity will be searching for evidence of ancient water in areas around Gediz Vallis Channel, with studies centered on how the channel formed. NASA scientists said they do not think wind formed it because the sides of it are too high. From space, the channel looks like an ancient riverbed, the agency said. Later, the channel filled with large rocks and other forms of debris³.

　　Last month, Curiosity documented the Gediz Vallis Channel with a 360-degree black-and-white picture captured by one of the rover's cameras.

　　The rover's new exploring activities can provide scientists with "a new way to study how the presence of both water and the chemical ingredients required for life changed over time," NASA said. The first formations to be examined contain sulfates, which are salty minerals often created when liquid water evaporates.

　　NASA said Curiosity also uncovered evidence of clay minerals in the Mount Sharp area. This suggests past interactions between large amounts of water and rock.

　　Movements of water and minerals can also produce a material called sediment⁴, particles that settle on the bottom of bodies of water over time. Examinations of these sediments⁵ can provide additional evidence of past water and possible life.

　　Ashwin Vasavada is a Curiosity project scientist with NASA's Jet Propulsion Laboratory in California. He said in a statement, "If the channel or the debris pile were formed by liquid water, that's very interesting."

　　Vasavada added, "It would mean that fairly late in the story of Mount Sharp – after a long dry period – water came back, and in a big way."

　　NASA currently operates two rovers on Mars. The other one, Perseverance⁶, has been exploring the planet's Jezero Crater since September 2021. It has collected rock, soil and atmospheric⁷ materials during that time. Jezero Crater is also believed to have contained large water bodies in the distant past.

　　Materials collected by the rovers are expected to be returned to Earth in the future. That effort, a joint⁸ mission between NASA and the European Space Agency (ESA), is planned for 2028.

　　Words in This Story

　　crater – n. a big hole left in the ground or an object by a force of impact

　　debris – n. broken pieces of something

　　clay –n. wet soil that is made of extremely fine particles

　　ingredient – n. a substance included in the preparation or production of something

　　evaporate – v. to change from a liquid into a gas or vapor

1 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。

2 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。

3 debris   

n.瓦砾堆，废墟，碎片

参考例句：

• After the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。
• Bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上，导致蛀牙。

4 sediment   

n.沉淀，沉渣，沉积(物)

参考例句：

• The sediment settled and the water was clear.杂质沉淀后，水变清了。
• Sediment begins to choke the channel's opening.沉积物开始淤塞河道口。

5 sediments   

沉淀物( sediment的名词复数 )； 沉积物

参考例句：

• When deposited, 70-80% of the volume of muddy sediments may be water. 泥质沉积物沉积后，体积的70-80％是水。
• Oligocene erosion had truncated the sediments draped over the dome. 覆盖于穹丘上的沉积岩为渐新世侵蚀所截削。

6 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。

7 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。

8 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。