Study: No Atmosphere Found on Nearby Earth-sized World

Study: No Atmosphere Found on Nearby Earth-sized World

The Webb Space Telescope has found no evidence of an atmosphere on one of the seven rocky, Earth-sized planets orbiting a nearby star.

Scientists said Monday that could mean the other planets in that system also lack atmospheres. Some of the planets are believed to be the right distance from the star to support water and possibly life. Scientists call this area the habitable zone.

Sara Seager is a scientist with Massachusetts Institute of Technology (MIT). She was not part of the study but spoke¹ to the Associated Press. She said in an email, "This is not necessarily a bust²" for the other planets. And she added, "But we will have to wait and see."

The planets orbit a star forming a system known as TRAPPIST-1 after the telescope that identified the planets. It is rare that seven planets about the size of our Earth would orbit the same star. Three of those planets are in the star's habitable zone.

TRAPPIST-1 is only 40 light-years away. A light year is the distance light travels in one year. That is relatively³ close to our own solar system and a reason why scientists are interested in it.

The NASA-led team reported little if any atmosphere exists on the innermost planet in the system. The results were published Monday in the journal Nature.

Thomas Greene of NASA's Ames Research Center is the lead researcher of the study. He said the lack of an atmosphere would mean no water and no protection from space radiation.

As for the other planets orbiting in the TRAPPIST-1 system, "I would have been more optimistic about the others" having atmospheres if this one had, Greene said in an email.

MIT's Seager said that if rocky planets orbiting the kind of star in the TRAPPIST-1 system, a very cool red dwarf⁴, "do turn out to be a bust, we will have to wait for Earths around sun-like stars, which could be a long wait."

The TRAPPIST-1 system's innermost planet receives four times as much solar radiation as Earth gets from the sun. Greene noted⁵ that it is possible that extra energy is why there is no atmosphere. His team said temperatures there reached 230 degrees Celsius⁶ on the side of the planet that is always facing its star.

The Webb is the largest and most powerful space telescope. By using Webb, the American and French scientists were able to measure the change in brightness as the innermost planet moved beyond its star. They then could estimate how much infrared⁷ light was sent off from the planet.

The change in brightness was very small since TRAPPIST-1 is more than 1,000 times brighter than this planet. The European Space Agency said Webb's detection of this light is itself a very large step.

More observations are planned not only of this planet, but the others in the system.

Taylor Bell of the Bay Area Environmental Research Institute took part in the study. He said looking at the innermost planet in another kind of light could uncover an atmosphere much thinner than our own, although it seems unlikely it could survive.

Michael Gillon of the University of Liege in Belgium was part of the team that discovered the first three planets in 2016. He did not take part in the latest study. He said further research could still uncover an atmosphere even if it is not like Earth's.

Gillon said scientists are entering new areas of research with rocky planets outside our solar system. Scientists' understanding of rocky planets is based on the four in our solar system: Mercury, Venus, Earth and Mars.

Webb was launched in late 2021 to an observation point 1.6 million kilometers away. It has taken over for the Hubble Space Telescope, which has orbited Earth for more than 30 years.

In the past, Hubble and the Spitzer Space Telescope searched the TRAPPIST-1 system for atmospheres but did not find any.

Julien de Wit of MIT was not involved in the study. But, he said, "It is just the beginning, and what we can learn with the inner planets is going to be different from what we can learn from the other ones."

Words in This Story

bust – n. a complete failure

cosmic – adj. of or relating to the universe or outer space

optimistic – adj. having or showing hope for the future

detect – v. to discover or notice the presence of (something that is hidden or hard to see, hear, or taste)

1 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

2 bust   

vt.打破；vi.爆裂；n.半身像；胸部

参考例句：

• I dropped my camera on the pavement and bust it. 我把照相机掉在人行道上摔坏了。
• She has worked up a lump of clay into a bust.她把一块黏土精心制作成一个半身像。

3 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

4 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。

5 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。

6 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。

7 infrared   

adj./n.红外线(的)

参考例句：

• Infrared is widely used in industry and medical science.红外线广泛应用于工业和医学科学。
• Infrared radiation has wavelengths longer than those of visible light.红外辐射的波长比可见光的波长长。