火星发现甲烷可能存在生命—pclinux,meteorobs&夜的眼睛
本帖最后由 一分半 于 2009-1-16 16:12 编辑现代快报1月16日报道 经过对火星多年探索之后，NASA（美国宇航局）的科学家终于在火星上发现了生命迹象。NASA于15日宣布，火星的冰层下面很可能生存着某种火星生命，它们释放出的甲烷气体在火星表面形成了一层薄雾。更激动人心的是，科学家相信，这些火星生命如今一定还活着，并且很可能正以一种“休眠”的状态存在，甚至可能再次复苏。
火星惊现“神秘薄雾”，“火星生命”大排废气
这一最新发现是NASA于1月15日在华盛顿总部宣布的。
NASA的科学家观察发现，火星部分地区表面存在着一层神秘的薄雾，在火星轨道上的太空船和地球上的巨型望远镜都能观测到这层“火星雾气”。而进一步研究表明，“火星雾气”的主要成分是甲烷气体，专家推测，这些甲烷气体正是由一种叫做“产烷生物”的火星生命释放出来的气体。
“火星生命”冰层下休眠？有可能再次复苏
NASA透露，这些“火星生命”很可能就生活在火星部分地区冰层下面的水中。更激动人心的是，科学家相信，这些“火星生命”如今一定还活着，否则火星的大气中将不可能有持续不断的甲烷。此外，NASA还在产生“火星雾气”同一地带发现了水蒸气形成的云层，而水正是维持生命至关重要的“饮料”。
排除火山喷发可能性，唯一来源是“火星生命”
不过，也有科学家对NASA的最新发现提出异议。持反对意见的科学家认为，火星表面的甲烷气体也可能是由火山运动造成的。但矛盾的是，目前火星上没有任何已知的活火山。
有史以来最重要发现，专家称火星存在“智慧生命”
据NASA表示，火星上由甲烷气体形成的“火星薄雾”是表明火星微生物至今仍存活的最新证据，而NASA的发现也证实了欧航局“火星快车号”探测器的研究成果，后者已经围绕火星运行了5年，2004年它也曾发现了火星上的甲烷迹象。 原来甲烷还分生物源和化学源哈~~~宇宙星际空间里也有有机分子,像甲醛这样的东西,从无机到有机,从非生命到生命的演变过程是很值得探究的~~
火星发现甲烷(合并贴)
本帖最后由 一分半 于 2009-1-16 11:21 编辑2009年01月16日03:48来源：现代快报
经过对火星多年探索之后，NASA（美国宇航局）的科学家终于在火星上发现了生命迹象。NASA于15日宣布，火星的冰层下面很可能生存着某种火星生命，它们释放出的甲烷气体在火星表面形成了一层薄雾。更激动人心的是，科学家相信，这些火星生命如今一定还活着，并且很可能正以一种“休眠”的状态存在，甚至可能再次复苏。
火星惊现“神秘薄雾”，“火星生命”大排废气
这一最新发现是NASA于1月15日在华盛顿总部宣布的NASA的科学家观察发现，火星部分地区表面存在着一层神秘的薄雾，在火星轨道上的太空船和地球上的巨型望远镜都能观测到这层“火星雾气”。而进一步研究表明，“火星雾气”的主要成分是甲烷气体，专家推测，这些甲烷气体正是由一种叫做“产烷生物”的火星生命释放出来的气体。
“火星生命”冰层下休眠？有可能再次复苏
NASA透露，这些“火星生命”很可能就生活在火星部分地区冰层下面的水中。更激动人心的是，科学家相信，这些“火星生命”如今一定还活着，否则火星的大气中将不可能有持续不断的甲烷。此外，NASA还在产生“火星雾气”同一地带发现了水蒸气形成的云层，而水正是维持生命至关重要的“饮料”。
排除火山喷发可能性，唯一来源是“火星生命”
不过，也有科学家对NASA的最新发现提出异议。持反对意见的科学家认为，火星表面的甲烷气体也可能是由火山运动造成的。但矛盾的是，目前火星上没有任何已知的活火山。
有史以来最重要发现，专家称火星存在“智慧生命”
据NASA表示，火星上由甲烷气体形成的“火星薄雾”是表明火星微生物至今仍存活的最新证据，而NASA的发现也证实了欧航局“火星快车号”探测器的研究成果，后者已经围绕火星运行了5年，2004年它也曾发现了火星上的甲烷迹象。旺旺
(责任编辑：guoqiang) 两位主题内容差不多,我就合并了哈~::070821_04.jpg:: 本帖最后由 那一片枫叶 于 2009-1-16 13:40 编辑
::070821_05.jpg::楼主这两天到火星去的时候吃洋葱吃多了，给各位带来困扰了。 抢个沙发。这可真是激动人心的消息。::070821_09.jpg::::070821_09.jpg:: LS说的那个甲烷含量应该不是很高的吧~~::42:: 额……我也不知道~~要不在标题里把你名字加上？::070821_04.jpg:: 不知道有没有确定是有生命是否肯定,还是.... 在那薄雾里点上一根火柴...... 本帖最后由 deepgreen 于 2009-1-16 18:50 编辑
期待发现火星地下牛场。。。以后去火星晚上烤火不用担心燃料了。。。还能随手牵几只牛大块烤牛肉吃。。。 额……谁要能从火星地底下找出牛来，那才真是牛咧~::070821_12.jpg:: 本帖最后由 q5968661 于 2009-1-16 21:44 编辑
还是看看相关原文吧。
Martian Methane Reveals the Red Planet is not a Dead
Mars today is a world of cold and lonely deserts, apparently without life of any kind, at least on the surface. Worse still, it looks like Mars has been cold and dry for billions of years, with an atmosphere so thin, any liquid water on the surface quickly boils away while the sun's ultraviolet radiation scorches the ground.
But there is evidence of a warmer and wetter past -- features resembling dry riverbeds and minerals that form in the presence of water indicate water once flowed through Martian sands. Since liquid water is required for all known forms of life, scientists wonder if life could have risen on Mars, and if it did, what became of it as the Martian climate changed.
New research reveals there is hope for Mars yet. The first definitive detection of methane in the atmosphere of Mars indicates the planet is still alive, in either a biologic or geologic sense, according to a team of NASA and university scientists.
"Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas," said Dr. Michael Mumma of NASA's Goddard Space Flight Center in Greenbelt, Md. "At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif."
http://www.nasa.gov/images/content/303609main_satreya_vid_01_1280_03.jpg
Scientists don't yet know enough to say with certainty what the source of the Martian methane is, but this artist's concept depicts a possibility. In this illustration, subsurface water, carbon dioxide and the planet's internal heat combine to release methane. Although we don’t have evidence on Mars of active volcanoes today, ancient methane trapped in ice "cages" might now be released. Credit: NASA/Susan Twardy
Methane -- four atoms of hydrogen bound to a carbon atom -- is the main component of natural gas on Earth. It's of interest to astrobiologists because organisms release much of Earth's methane as they digest nutrients. However, other purely geological processes, like oxidation of iron, also release methane. "Right now, we don’t have enough information to tell if biology or geology -- or both -- is producing the methane on Mars," said Mumma. "But it does tell us that the planet is still alive, at least in a geologic sense. It's as if Mars is challenging us, saying, hey, find out what this means." Mumma is lead author of a paper on this research appearing in Science Express Jan. 15.
If microscopic Martian life is producing the methane, it likely resides far below the surface, where it's still warm enough for liquid water to exist. Liquid water, as well as energy sources and a supply of carbon, are necessary for all known forms of life.
"On Earth, microorganisms thrive 2 to 3 kilometers (about 1.2 to 1.9 miles) beneath the Witwatersrand basin of South Africa, where natural radioactivity splits water molecules into molecular hydrogen (H2) and oxygen. The organisms use the hydrogen for energy. It might be possible for similar organisms to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon," said Mumma.
"Gases, like methane, accumulated in such underground zones might be released into the atmosphere if pores or fissures open during the warm seasons, connecting the deep zones to the atmosphere at crater walls or canyons," said Mumma.
"Microbes that produced methane from hydrogen and carbon dioxide were one of the earliest forms of life on Earth," noted Dr. Carl Pilcher, Director of the NASA Astrobiology Institute which partially supported the research. "If life ever existed on Mars, it's reasonable to think that its metabolism might have involved making methane from Martian atmospheric carbon dioxide."
However, it is possible a geologic process produced the Martian methane, either now or eons ago. On Earth, the conversion of iron oxide (rust) into the serpentine group of minerals creates methane, and on Mars this process could proceed using water, carbon dioxide, and the planet's internal heat. Although we don’t have evidence on Mars of active volcanoes today, ancient methane trapped in ice "cages" called clathrates might now be released.
The team found methane in the atmosphere of Mars by carefully observing the planet over several Mars years (and all Martian seasons) with NASA's Infrared Telescope Facility, run by the University of Hawaii, and the W. M. Keck telescope, both at Mauna Kea, Hawaii.
The team used spectrometer instruments attached to the telescopes to make the detection. Spectrometers spread light into its component colors, like a prism separates white light into a rainbow. The team looked for dark areas in specific places along the rainbow (light spectrum) where methane was absorbing sunlight reflected from the Martian surface. They found three such areas, called absorption lines, which together are a definitive signature of methane, according to the team. They were able to distinguish lines from Martian methane from the methane in Earth's atmosphere because the motion of the Red Planet shifted the position of the Martian lines, much as a speeding ambulance causes its siren to change pitch as it passes by.
"We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane," said Dr. Geronimo Villanueva of the Catholic University of America, Washington, D.C. Villanueva is stationed at NASA Goddard and is co-author of the paper. "The plumes were emitted during the warmer seasons -- spring and summer -- perhaps because the permafrost blocking cracks and fissures vaporized, allowing methane to seep into the Martian air. Curiously, some plumes had water vapor while others did not," said Villanueva.
According to the team, the plumes were seen over areas that show evidence of ancient ground ice or flowing water. For example, plumes appeared over northern hemisphere regions such as east of Arabia Terra, the Nili Fossae region, and the south-east quadrant of Syrtis Major, an ancient volcano 1,200 kilometers (about 745 miles) across.
It will take future missions, like NASA's Mars Science Laboratory, to discover the origin of the Martian methane. One way to tell if life is the source of the gas is by measuring isotope ratios. Isotopes are heavier versions of an element; for example, deuterium is a heavier version of hydrogen. In molecules that contain hydrogen, like water and methane, the rare deuterium occasionally replaces a hydrogen atom. Since life prefers to use the lighter isotopes, if the methane has less deuterium than the water released with it on Mars, it's a sign that life is producing the methane. The research was funded by NASA's Planetary Astronomy Program and the NASA Astrobiology Institute. 那么多IF，让人如何相信！ 牛年去火星发牛财 不知道火星探测器能不能带过去几个细菌么？
ring_3_ 发表于 2009-1-20 12:27 http://www.astronomy.com.cn/bbs/images/common/back.gif
看过Discovery的一个片子,说细菌可以承受长时间真空、高温和高速撞击，这个不能说没有可能啊~::070821_12.jpg::
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