VOA科学技术2024--New Data Suggests Jupiter’s Moon Europa Has Less Oxygen than Expected

New Data Suggests Jupiter’s Moon Europa Has Less Oxygen than Expected

　　A new study suggests Jupiter's icy moon Europa produces much less oxygen than previously¹ thought.

　　The study was based on data collected by the American space agency NASA's Juno spacecraft. Juno is an orbiter that has been studying Jupiter since July 2016.

　　The study involved Juno's instruments measuring levels of oxygen and hydrogen molecules² coming from Europa's atmosphere. The data showed the icy moon produces about 1,000 tons of oxygen every 24 hours. NASA said that amount would be enough "to keep a million humans breathing for a day.

　　However, the space agency noted³ those oxygen level estimates were "substantially less" than those measured in earlier studies about the moon.

　　Europa is a little smaller than Earth's moon. But it is still one of the largest in our solar system. NASA observations have suggested an ocean exists beneath a thick layer of ice on Europa's surface. Scientists estimate the moon's ocean may contain twice the amount of water as Earth's oceans.

　　The new study is based on data Juno collected in 2022 during a particularly close flyby of Europa. The flyby is believed to have brought the spacecraft within 350 kilometers of the moon.

　　The research was led by teams from Princeton University in New Jersey⁴ and Maryland's Southwest Research Institute. The scientists estimated Europa is producing around 12 kilograms of oxygen per second. Earlier predictions suggested the moon was releasing up to 1,000 kilograms per second.

　　Since Europa is believed to have a large ocean under its surface, researchers in the past identified it as a good candidate to hold the right conditions to support some form of life. That data came mainly from telescope observations of oxygen levels existing in the moon's icy surface.

　　The new, lower oxygen estimates do not support the earlier observations. The team involved in the study said more research will be needed to confirm the latest findings.

　　Scott Bolton is a Juno investigator⁵ at the Southwest Research Institute and a co-writer of the study. He said in a statement that the team's new findings have a direct effect on the possibility that Europa could be habitable. While the oxygen amounts measured were much lower, the latest study gives scientists "a narrow range that could support habitability," Bolton said.

　　Princeton University researcher Jamey Szalay was the study's lead writer. He said, "The findings unambiguously demonstrate oxygen is continuously produced at the surface, just a good bit lower than we expected."

　　Szalay added that Juno's flyby of Europa marked the first time a spacecraft was able to directly measure the moon's atmosphere. "We couldn't wait to peek⁶ behind the curtain of its complex environment," he wrote to The Associated Press in an email.

　　The researchers said the new measurements can help scientists gain a better understanding of Europa and its environment, and "open the door for newer, more precise models."

　　Robert Ebert is a researcher at the Southwest Research Institute and a co-writer of the study. He said that even with the new results, he believes further investigations⁷ should take place to search for signs of life on Europa. "Water is important for the existence of life... Europa is a good place to search for water within our solar system."

　　NASA hopes to launch its Europa Clipper mission in October. This orbiter is designed to carry out close examinations of Europa. It will look for signs it might hold the right conditions to support life.

　　NASA says the orbiter plans to fly in orbit around Jupiter and "perform repeated close flybys of the ice moon."

　　Words in This Story

　　substantial – n. large in amount

　　habitable – adj. able to support life

　　unambiguous – n. expressed in a very clear way

　　peek behind the curtain – n. get a look at something not normally seen

　　precise – adj. very clear or exact

1 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

2 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

3 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

4 jersey   

n.运动衫

参考例句：

• He wears a cotton jersey when he plays football.他穿运动衫踢足球。
• They were dressed alike in blue jersey and knickers.他们穿着一致，都是蓝色的运动衫和灯笼短裤。

5 investigator   

n.研究者，调查者，审查者

参考例句：

• He was a special investigator for the FBI.他是联邦调查局的特别调查员。
• The investigator was able to deduce the crime and find the criminal.调查者能够推出犯罪过程并锁定罪犯。

6 peek   

vi.偷看，窥视；n.偷偷的一看，一瞥

参考例句：

• Larry takes a peek out of the window.赖瑞往窗外偷看了一下。
• Cover your eyes and don't peek.捂上眼睛，别偷看。

7 investigations   

（正式的）调查( investigation的名词复数 )； 侦查； 科学研究； 学术研究

参考例句：

• His investigations were intensive and thorough but revealed nothing. 他进行了深入彻底的调查，但没有发现什么。
• He often sent them out to make investigations. 他常常派他们出去作调查。