| A disk of gas and dust 450 light-years away bears a close resemblance to our early solar system, astronomers report. The region contains relatively large quantities of some of the most important basic building blocks of life, and these are concentrated at a potentially habitable distance away from the parent star. The finding should provide new insights into how life managed to arise in our own neighborhood. |
据天文学家们报道，一个由气体和尘埃构成的圆盘位于450光年以外，跟我们早期的太阳系极为相似。相对来说，其中包含大量的、某些最重要的生命基础材料，这些材料集中之处跟主恒星的距离适中，具有潜在的可居住性。至于我们周围的生命是如何产生的，该发现应该能够提供新的认识。 |
| Over the past couple of decades, astronomers have been able to detect hundreds of disks of dust and gas surrounding very young stars, which signify new planets in the making. The key to understanding the evolution of these protoplanets--and whether they might spawn life--lies in getting a closer look. "Until now, it has only been possible to see gas very near the star or very far from it," says astronomer Dan Watson of the University of Rochester in New York. But the enhanced instruments aboard NASA's Spitzer Space Telescope are breaching that barrier in a critical way: by detecting extremely subtle differences in wavelengths of infrared light, enough to isolate the nature and quantities of simple organic molecules. |
在过去的几十年里，天文学家们在非常年轻的恒星周围发现了数以百计的尘埃和气体圆盘，而且其中有新行星正在形成的迹象。不管是否会产生生命，了解这些原行星演化情况的关键在于进行更加仔细地观察。“到目前为止，只是有可能观察距恒星很近或者很远的气体，”纽约罗彻斯特大学的天文学家丹·沃森说。美国航空航天管理局的斯必泽太空望远镜上搭载的仪器功能有所强化，克服了一个主要障碍，能够通过探测红外光各种波长中极其细微的差别，足以将简单有机分子的数量和性质分析清楚。 |
| Astronomers John Carr of the Naval Research Laboratory in Washington, D.C., and Joan Najita of the National Optical Astronomy Observatory in Tucson, Arizona, used Spitzer to tease out the signals revealing the molecular composition of the gas in the disk surrounding AA Tauri, a star less than a million years old located in the constellation Taurus. The spacecraft's sensitive spectrometer was able to register the chemical signatures not only of water vapor but also of hydrogen cyanide, carbon monoxide, and carbon dioxide--all precursors of the more complex molecules that scientists think eventually gave rise to life on Earth. |
华盛顿哥伦比亚特区海军研究实验室的天文学家约翰·卡尔，和亚利桑那州图森国家光学天文台的天文学家琼·纳吉塔，利用斯必泽太空望远镜挑选出能够揭示恒星“AA托莱”周围圆盘中气体分子构成情况的信号。恒星“AA托莱”位于金牛座，诞生于不到一百万年前。斯必泽太空望远镜上敏感的光谱仪不但能够记录水蒸气的化学特征，还能够记录氰化氢、一氧化碳和二氧化碳的化学特征，这些都是更为复杂分子的初级粒子，科学家们认为是这些初级粒子最终导致了地球生命的产生。 |
| Other astronomers have detected these molecules before in interstellar space, but the researchers report in tomorrow's issue of Science that they have pinpointed the location of these molecules in AA Tauri's disk, which means they might have been manufactured there. They are in a zone located about three times the distance from the star as Earth is from the sun--still close enough, theoretically, to coalesce into more complex molecules from which life could spring. This is the first time simple organic molecules and water have been found lurking around another star at Earth-like distances, the team reports. |
其他的天文学家们以前在星际空间发现过这些分子，但是研究人员们在明天的出版的《科学》杂志上报道说：他们找出了这些分子在“AA托莱”圆盘中的具体位置，这意味着这些分子可能是就地形成的。这些分子所处位置距离主恒星大约是地球距离太阳的三倍，从理论上说距离仍算很近，足以形成更为复杂的分子，导致生命的产生。研究小组报道说：这是首次发现简单的有机分子和水存在于类似地球距离太阳的位置上，潜伏在另外一个恒星周围。 |
| "The abundance [of the molecules] we measured provide new clues to how molecules are created, destroyed, or transported in disks," Najita says. "These clues may ultimately help us answer questions such as whether the chemical precursors for life are commonly created in planet-forming disks." Carr adds that these are critical details for "understanding the details of how both Earth-like and Jupiter-like planets are formed." |
“我们探测到丰富的简单有机分子，为研究它们在圆盘中如何产生、运动、及毁灭提供了新线索，”纳吉塔说，“这些线索最终可以帮助我们解决相关问题，如：正在形成行星的圆盘中是否会普遍存在生命所需的化学初级粒子，等问题。”卡尔接着指出：“这些关键的详细资料有助于详细了解类地行星和类木行星的形成情况。” |
| The study represents "a major advance in our understanding of protoplanetary disks and their evolution," Watson says. And astronomer Zoltan Balog of the Steward Observatory in Tucson, Arizona, says he thinks the research "basically means that protoplanetary disks might be able to produce prebiotic molecules and ultimately the basic building blocks for life at the place where an Earth would form." |
沃森说：“在对原行星盘及其演化情况的理解上，该研究取得了较大的进展。”亚利桑那州图森史都华天文台的天文学家左坦·巴洛格说：“我认为，从根本上说，该研究意味着原行星盘中可能会产生生命源起分子，而且最终在行星形成的地方产生构成生命的基本材料。” |
