엄청난 뉴스를 접하고 바로 해석해서 포스팅 합니다.

외부 태양계를 관찰하던중, 나사의 연구원들이 '생명을 위한 기초 유기 화합물'을 발견했습니다. 발견된 행성은 거주하기에 적합한 행성은 아니지만, 주변에서 암석성운을 발견한다면 생명이 존재할 수도 있게 됩니다.

이것은 태양계 외부에서 물, 메탄 그리고 탄소가 있고 생명이 거주할 수 있는 지역에서 발견된 두번째 행성 이라는군요.

이번에 발견된 것은 HD 209458b 라는 가스행성으로 페가수스 자리에 속한 별로서 지구에서 150광년 정도 떨어진 태양과 비슷한 크기의 항성을 도는 목성보다 크고, '뜨거운' 행성입니다. 그리고, 지난번에 발견된 행성은 HD 189733b 라는 행성으로서 (2008년 12월 발견) 목성과 비슷한 크기라 하는군요.

기사의 주요내용을 번역했지만, 간만에 해보는 영문번역인지라 미흡한 점이 많을듯 합니다. ;

어쨌건, 이것으로 생명권 (공전궤도가 물이 액체로서 존재할 수 있는 권역을 지나는 행성) 에 존재하는 행성이 벌써 두개째 발견되었군요. 둘 다 가스행성이긴 하지만, 목성의 예를 볼 때 그 위성으로서 암석으로 된 행성(위성)이 존재할 확률이 높고, 그 모행성에 의한 조석현상으로 지질 활동이 활발할 것이 예상되니 외계 생명체의 존재도 상당히 긍정적으로 보일듯 합니다. 물론, 자세한 것은 조금 더 관측해봐야 알겠지만, 점점 외계 생명체가 존재할 확률이 높아져 가는 것은 사실인듯 하군요. 거기다 '메탄'. '이산화탄소' 와 같은 생명활동으로 인한 화합물까지 발견되었으니!

아래는 기사 원문입니다.


Astronomers do it Again: Find Organic Molecules Around Gas Planet

Peering far beyond our solar system, NASA researchers have detected the basic chemistry for life in a second hot gas planet, advancing astronomers toward the goal of being able to characterize planets where life could exist. The planet is not habitable but it has the same chemistry that, if found around a rocky planet in the future, could indicate the presence of life.

"It's the second planet outside our solar system in which water, methane and carbon dioxide have been found, which are potentially important for biological processes in habitable planets," said researcher Mark Swain of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Detecting organic compounds in two exoplanets now raises the possibility that it will become commonplace to find planets with molecules that may be tied to life."

Swain and his co-investigators used data from two of NASA's orbiting Great Observatories, the Hubble Space Telescope and Spitzer Space Telescope, to study HD 209458b, a hot, gaseous giant planet bigger than Jupiter that orbits a sun-like star about 150 light years away in the constellation Pegasus. The new finding follows their breakthrough discovery in December 2008 of carbon dioxide around another hot, Jupiter-size planet, HD 189733b. Earlier Hubble and Spitzer observations of that planet had also revealed water vapor and methane.

The detections were made through spectroscopy, which splits light into its components to reveal the distinctive spectral signatures of different chemicals. Data from Hubble's near-infrared camera and multi-object spectrometer revealed the presence of the molecules, and data from Spitzer's photometer and infrared spectrometer measured their amounts.

"This demonstrates that we can detect the molecules that matter for life processes," said Swain. Astronomers can now begin comparing the two planetary atmospheres for differences and similarities. For example, the relative amounts of water and carbon dioxide in the two planets is similar, but HD 209458b shows a greater abundance of methane than HD 189733b. "The high methane abundance is telling us something," said Swain. "It could mean there was something special about the formation of this planet."

Other large, hot Jupiter-type planets can be characterized and compared using existing instruments, Swain said. This work will lay the groundwork for the type of analysis astronomers eventually will need to perform in shortlisting any promising rocky Earth-like planets where the signatures of organic chemicals might indicate the presence of life.

Rocky worlds are expected to be found by NASA's Kepler mission, which launched earlier this year, but astronomers believe we are a decade or so away from being able to detect any chemical signs of life on such a body.

If and when such Earth-like planets are found in the future, "the detection of organic compounds will not necessarily mean there's life on a planet, because there are other ways to generate such molecules," Swain said. "If we detect organic chemicals on a rocky, Earth-like planet, we will want to understand enough about the planet to rule out non-life processes that could have led to those chemicals being there."

"These objects are too far away to send probes to, so the only way we're ever going to learn anything about them is to point telescopes at them. Spectroscopy provides a powerful tool to determine their chemistry and dynamics."

You can follow the history of planet hunting from science fiction to science fact with NASA's PlanetQuest Historic Timeline at http://planetquest.jpl.nasa.gov/timeline/ .

This interactive web feature, developed by JPL, conveys the story of exoplanet exploration through a rich tapestry of words and images spanning thousands of years, beginning with the musings of ancient philosophers and continuing through the current era of space-based observations by NASA's Spitzer and Kepler missions. The timeline highlights milestones in culture, technology and science, and includes a planet counter that tracks the pace of exoplanet discoveries over time.

More information about exoplanets and NASA's planet-finding program is at http://planetquest.jpl.nasa.gov .

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency and is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The Space Telescope Science Institute, Baltimore, Md., conducts Hubble science operations. The institute is operated for NASA by the Association of Universities for research in Astronomy, Inc., Washington, D.C.

JPL manages the Spitzer Space Telescope mission for NASA. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
 
 
Written by Mary Beth Murrill
Media contact: Whitney Clavin/Jet Propulsion Laboratory 818-354-4671

 - 원문 출처 : http://www.nasa.gov/mission_pages/spitzer/news/spitzer-20091020.html


'Universe > NASA' 카테고리의 다른 글

Thin Blue Line  (9) 2009.11.27
The Birth of Stars (별의 탄생)  (18) 2009.11.13
태양계 외부에서 발견된 유기물의 흔적  (10) 2009.10.21
토성의 The Rite of Spring (봄의 제전)  (18) 2009.10.18
안드로메다 은하 (Andromeda galaxy, M31)  (18) 2009.10.18
화성, 물이 흐른 흔적  (10) 2009.10.07


티스토리 툴바