本帖最后由 Lagrange 于 2009-10-25 18:08 编辑
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.
向我们太阳系以外窥视,NASA的研究人员已经在第二个高温气体星球上检测到了生命基本化学成分,随着研究的深入,很可能发现具有生命表征的星球。这颗星球是不适宜居住的,但是其具有生命存在必须的化学成分,如果将来能对周围岩石构成的行星探索,可能发现生命的存在。
"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."
JPL研究人员Mark Swain说:这是在太阳系外迄今发现的第二颗具有水,甲烷和二氧化碳成分的星球,在适宜居住的行星里这是潜在的重要生物过程。对两个系外行星的有机物探测说明了一种可能性,即生构成生命的化学成分在宇宙中存在普适性。
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.
Swain和他的研究人员使用NASA的轨道大天文台,哈勃和斯皮策红外天文望远镜,研究了位于距地球150光年的飞马座,编号为HD 209458b,体积大于木星的巨型气态行星,其围绕着一颗类似太阳的恒星旋转。在2008年,类似的突破性发现为在编号为HD 189733b类木行星上发现二氧化碳的踪迹。
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.
明显这样的发现应该通过光谱分析。来自哈勃近红外相机和多目标光谱仪的数据揭示了分子的存在,来自斯皮策的光度计数据和红外光谱仪测定分子数量。
"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."
这表明我们能检测分子种类来推测其是否具备潜在的生命演化过程。天文学家能开始比较两个不同星球的大气成分。例如水和二氧化碳在这两颗星球上的相对含量是相似的,但是HD 209458b的数据表明其甲烷的含量比HD 189733b的要丰富。这个信息告诉我们,HD 209458b的大气成分以及星球构成比较特殊点。
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.
其他的大型类木行星可以使用现有的技术手段确定并进行对比。这项工作将奠定分析类型的基础,天文学家最终将寄希望于具有岩石表面特征的类地行星上,如果这类行星上发现支持生命的化学成分,则可能表明有生命存在。
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.
NASA的开普勒空间望远镜则承担着探索系外类地行星任务,天文学家相信我在下一个十年左右能发现具有生命化学特征的类地行星。
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."
如果将来发现此类类地行星具有有机化学成分,但是这也不一定意味着其具有生命,因为有很多途径可以产生这类分子。如果我们在一颗类地行星上发现有机物成分,我们将对其深入了解,以确定这些化学成分是不是在生命过程中产生的。
"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."
这些天体离我们相当遥远,不可能通过发射探测器进行研究,所以只能通过空间望远镜,通过光谱分析来确定其化学成分。
http://spitzer.caltech.edu/news/974-feature09-12-Astronomers-Do-It-Again-Find-Organic-Molecules-Around-Gas-Planet
http://www.nasa.gov/mission_pages/spitzer/news/spitzer-20091020.html |
评分
-
查看全部评分
|