VOA科学技术2024--Astronomers Find Super-hot 'Super-Earth'

Astronomers¹ have searched for years for rocky planets outside our solar system. They have finally found one with an atmosphere.

Scientists believe that a rocky planet with an atmosphere is key to sustaining life. But the planet that astronomers found offers no hope for life. Its surface is made up of molten rock.

Researchers recently called the planet a "super-Earth." It is a rocky world much larger than our planet but smaller than the gas giant in our solar system, Neptune².

The planet orbits extremely close to its star. The star is less bright and smaller than our own.

Observations using two devices aboard the James Webb Space Telescope suggest there is an atmosphere. But the atmosphere may not be able to support life. It could be continuously filled up by gases that large areas of molten rock release.

Renyu Hu is a planetary scientist with NASA's Jet Propulsion Laboratory and California Institute of Technology. He was the lead writer of the study, which appeared recently in the publication Nature.

Hu said, "The atmosphere is likely rich in carbon dioxide or carbon monoxide, but can also have other gases such as water vapor³ and sulfur⁴ dioxide." He added that current observations cannot tell what the exact atmospheric⁵ makeup⁶ is.

The Webb data also did not make clear the thickness of the atmosphere. Hu said it could be as thick as Earth's or even thicker than that of Venus. Venus has a toxic⁷ atmosphere that is the densest⁸ in our solar system.

The planet is called 55 Cancri e. Scientists also call it Janssen. It is about 8.8 times more massive than Earth and about two times as wide.

It orbits its star at one-25th the distance between our solar system's innermost planet Mercury and the sun. As a result, its surface temperature is about 1,725 degrees Celsius⁹.

One side of the planet probably always faces its star. Four other planets, all gas giants, are known to orbit the same star. The planet is found in our Milky¹⁰ Way galaxy¹¹, about 41 light-years from Earth. A light-year is the distance light travels in a year, or 9.5 trillion kilometers.

The planet's star is gravitationally tied to another star in the system. Having two stars in the same system is called a binary¹² system.

The other star is a red dwarf¹³, the smallest kind of an ordinary star. The distance between these two stars is 1,000 times the distance between Earth and the sun. Light from one star takes six days to reach the other star.

Although the rocky planet does appear to have an atmosphere, scientists say it probably should not even have one. Being so close to its star, any atmosphere should be taken away by the effects of the star.

But gases dissolved in the planet's large ocean of molten rock may continue to fill up the atmosphere, Hu said.

"The planet cannot be habitable," Hu added. That is because it is too hot to have liquid water, which is also considered necessary for life.

Scientists have found other planets with an atmosphere outside our solar system. But they have all been gaseous¹⁴ planets, not rocky ones.

As the James Webb telescope pushes the limits of space exploration, the discovery of a rocky planet with an atmosphere is a sign of progress.

On Earth, the atmosphere warms the planet. It contains the oxygen people breathe and protects against the effects of the sun. It also creates the pressure needed for liquid water to remain on the planet's surface.

Brice-Olivier Demory is a scientist at Switzerland's University of Bern's Center for Space and Habitability. He helped write the new study. He said, "On Earth, atmosphere is key for life." He added that the findings create hope that the Webb telescope may one day find cooler planets that could support liquid water on their surface.

"But," he said, "we are not there yet."

Words in This Story

solar system - n. our sun and the planets that move around it

molten - adj. melted by heat

vapor - n. a substance that is in the form of a gas or that consists of very small drops or particles mixed with the air

giant - adj. very large

galaxy - n. any one of the very large groups of stars that make up the universe

habitable - adj. suitable or fit to live in

1 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

2 Neptune   

n.海王星

参考例句：

• Neptune is the furthest planet from the sun.海王星是离太阳最远的行星。
• Neptune turned out to be a dynamic,stormy world.海王星原来是个有生气、多风暴的世界。

3 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

4 sulfur   

n.硫，硫磺（=sulphur）

参考例句：

• Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
• Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。

5 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。

6 makeup   

n.组织；性格；化装品

参考例句：

• Those who failed the exam take a makeup exam.这次考试不及格的人必须参加补考。
• Do you think her beauty could makeup for her stupidity?你认为她的美丽能弥补她的愚蠢吗？

7 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

8 densest   

密集的( dense的最高级 )； 密度大的； 愚笨的； （信息量大得）难理解的

参考例句：

• Past Botoi some of the densest jungle forests on Anopopei grew virtually into the water. 过了坊远湾，岛上的莽莽丛林便几乎直长到水中。
• Earth is the densest of all of these remaining planets. 地球是所剩下行星中最致密的星球。

9 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

10 milky   

adj.牛奶的，多奶的；乳白色的

参考例句：

• Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
• I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。

11 galaxy   

n.星系；银河系；一群(杰出或著名的人物)

参考例句：

• The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。

12 binary   

adj.二，双；二进制的；n.双(体)；联星

参考例句：

• Computers operate using binary numbers.计算机运行运用二进位制。
• Let us try converting the number itself to binary.我们试一试，把这个数本身变成二进制数。

13 dwarf   

n.矮子，侏儒，矮小的动植物；vt.使…矮小

参考例句：

• The dwarf's long arms were not proportional to his height.那侏儒的长臂与他的身高不成比例。
• The dwarf shrugged his shoulders and shook his head. 矮子耸耸肩膀，摇摇头。

14 gaseous   

adj.气体的，气态的

参考例句：

• Air whether in the gaseous or liquid state is a fluid.空气，无论是气态的或是液态的，都是一种流体。
• Freon exists both in liquid and gaseous states.氟利昂有液态和气态两种形态。