时间:2024-11-21 18:19:06 来源:网络整理编辑:綜合
The search for a rocky world swaddled in a protective atmosphere somewhere else in space has eluded
The search for a rocky world swaddled in a protective atmosphere somewhere else in space has eluded scientists, but the James Webb Space Telescope has found a strong case.
Webb, the leading infrared observatory run by NASA and the European and Canadian space agencies, has taken a closer look at super-Earth 55 Cancri e, an exoplanet blanketed in either carbon dioxide or carbon monoxide just 41 light-years away.
But to call it an "Earth-like world" would be misleading. Discovered 13 years ago in the constellation Cancer, the planet seems to orbit so close to its star, its surface is probably lava. And because it's hugging the star so tightly, chances are it isn't rotating either, with one side in constant darkness.
Still, the discovery could be the best evidence scientists have found of a rocky planet's atmosphere outside Earth's own solar system. Such a finding, published in the journal Nature, bolsters experts' confidence that they'll eventually discover rocky worlds with hospitable atmospheres.
"Webb is pushing the frontiers of exoplanet characterization to rocky planets," said Renyu Hu, a researcher at NASA's Jet Propulsion Laboratory, in a statement. "It is truly enabling a new type of science."
SEE ALSO:Webb may have just found an Earth-like world with an atmosphereTweet may have been deleted
When exoplanets cross in front of their host star, the star’s light is filtered through that atmosphere. Molecules within the atmosphere absorb certain light wavelengths, or colors, so by splitting the star’s light into its basic parts — a rainbow — astronomers can use Webb to detect what light segments are missing and discern the molecular makeup of an atmosphere.
Scientists have found signs of atmospheres surrounding many exoplanets over the past 20 years, but all of them have been gas giant planets, like Jupiter, with thick atmospheres mostly composed of hydrogen.
Knowing what's in another planet's atmosphere is important. NASA has playfully called Earth's own atmosphere its "security blanket": Without it, the type of life flourishing on the planet wouldn't exist. This cocoon holds oxygen in the air and filters out harmful ultraviolet radiation from the sun, all while keeping our world warm and habitable. Furthermore, it creates pressure that allows liquid water to exist on Earth's surface.
NASA made a travel poster-inspired illustration of what the exoplanet 55 Cancri e might look like.Credit: NASA / JPL-Caltech illustrationThe first sign that 55 Cancri e could have a substantial atmosphere came from temperature readings based on the infrared light it radiates. If the planet is covered in dark molten rock with no atmosphere — or a very thin one of vaporized rock — the side in constant light should be about 4,000 degrees Fahrenheit.
Instead, the researchers found a much lower temperature of about 2,800 degrees Fahrenheit.
"Webb is pushing the frontiers of exoplanet characterization to rocky planets," said Renyu Hu, a researcher at NASA's Jet Propulsion Laboratory.Credit: NASA GSFC / CIL / Adriana Manrique Gutierrez illustration"This is a very strong indication that energy is being distributed from the dayside to the nightside, most likely by a volatile-rich atmosphere," Hu said.
While 55 Cancri e would seem far too hot to support life as we know it, scientists think studying it could enhance their understanding of the primitive conditions of Earth, Venus, and Mars, which some believe were also once covered in magma oceans.
"Ultimately, we want to understand what conditions make it possible for a rocky planet to sustain a gas-rich atmosphere: a key ingredient for a habitable planet,” Hu said.
TopicsNASA
Whyd voice2024-11-21 18:02
吉翔手係江蘇隊圍巾捧冠軍獎杯 :我在齊魯 遙望江東2024-11-21 17:42
風波停息!盧卡庫麵談和解圖赫爾 將繼續效力切爾西2024-11-21 17:40
官方:沈夢露與葡萄牙體育解約 曝因出場時間過少2024-11-21 17:40
Olympian celebrates by ordering an intimidating amount of McDonald's2024-11-21 17:33
開啟留洋之旅!李磊啟程飛往瑞士 國安球迷上海送行(圖)2024-11-21 17:31
中超保級神劇情 !90分鍾多次反轉 大連人贏球仍踢附加賽2024-11-21 17:14
好消息 !邱芳芳幹細胞移植有新進展 一切順利可在5月進行移植2024-11-21 16:54
'Rocket League' Championship Series Season 2 offers $250,000 prize pool2024-11-21 16:51
張效瑞:希望為賽季畫圓滿句號 下賽季俱樂部會有更好安排2024-11-21 16:35
Here's George Takei chilling in zero gravity for the 'Star Trek' anniversary2024-11-21 17:43
天津津門虎發文感謝球迷 :是我們一起完成了保級回家的目標2024-11-21 17:32
轉會通 :因西涅轉投美國大聯盟 庫鳥同意離開巴薩2024-11-21 17:27
武漢VS重慶首發 :單外援PK全華班 姚翰林告別戰先發2024-11-21 17:22
Fiji wins first2024-11-21 17:14
滄州主帥 :球隊今天運氣不太好 向津門虎表示祝賀2024-11-21 16:54
張效瑞:希望為賽季畫圓滿句號 下賽季俱樂部會有更好安排2024-11-21 16:51
主帥當選最佳!官方:鄭智當選中超第21輪最佳球員2024-11-21 16:05
Nancy Pelosi warns colleagues after info hacked2024-11-21 15:54
葡萄牙體育官宣與沈夢露解約 加盟僅半年將繼續留洋2024-11-21 15:35