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Focus on popular science chasing stars 12 years Rosetta tower catch up with what — people’s network-googims

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The focus of Science: "engaged in" 12 years "Rosetta" to what — people.com.cn Hainan window, people.com.cn 30 noon local time, confirm the European Space Agency is located in Paris, Rosetta comet probe has successfully planned to hit "comet 67P / Churyumov Guerra Simeon C (hereinafter referred to as" 67P "") surface, ending 12 years of "Zhuixing" tour. The probe was launched in March 2, 2004, its mission is to catch up with the "67P" and put on the Philae lander, explore the mystery of the origin of the solar system. "Rosetta" weighs about 3 tons, volume of about 12 cubic meters. It is equipped with 10 scientific instruments that can analyze the physical and chemical composition of comets and their electromagnetic and gravitational properties. "67P" was born 4 billion 600 million years ago at the beginning of the solar system. Unlike the earth’s frequent geological changes, the comet has little change inside, like a flying "refrigerator" that may preserve the most primitive material at the time of the solar system. Therefore, the study of comets helps to uncover many mysteries of the formation of the solar system. 12 years long, "star chasing" journey finally successfully ended, "Rosetta tower" in the end catch up with what? – to take pictures of comet nucleus divided into nucleus and coma and tail of three parts, of which the nucleus is usually considered a solid part of the comet center. The research results of the Rosetta "on the" 67P "shows that the overall shape of the nucleus showed double flap structure, including the smaller" head "," large body "and connect the two parts of the neck". In the "HD picture Rosetta shot, you can see the" neck "across a treaty 500 meters long clear cracks. "Pictures of about 70% of the surface of the comet nucleus Rosetta, the invisible part of the comet is located in the southern hemisphere. The imaged area can be divided into 5 geological forms: dust covered area, rock surface area, small pit structure and ring structure area, large depression area and smooth zone area. The various geological formations are unexpected, because comets are generally considered to be composed of the same material in general, and their surface geological forms should be approximately the same. The photos also show "67P" on the surface of the sand dunes ripple structure, some stone is also "blowing" out of the wind tail, but comets are not like the earth as windy. The researchers believe that this may be because the comet when heated ice volatile form of atmospheric dust or coma, with the escape of gas, but not fast enough and fall back to the comet surface, formed the special geological features. Negative magnetic field "Rosetta" observations show that there is no magnetic field on the "67P", which may allow scientists to re understand the solar system. It was surprising that the moon rock samples and meteorites were found to have strong magnetic fields, and there was no evidence of a magnetic field on the "67P". Previous observations suggest that if the comet has a magnetic field, it may explain how its constituent material gathered together in the early stages of the solar system, and this new discovery in the target comet suggests that the above view may not be true. Discovery of a variety of organic compounds 2014)

焦点科普:“追星”12年“罗塞塔”追到了什么–人民网海南视窗–人民网   当地时间30日中午,总部位于巴黎的欧洲航天局确认,“罗塞塔”彗星探测器已成功按计划撞向彗星“67P/丘留莫夫-格拉西缅科”(下称“67P”)表面,结束了12年“追星”之旅。   这颗探测器于2004年3月2日发射升空,其任务是追上“67P”并投放“菲莱”着陆器,探求太阳系起源的奥秘。“罗塞塔”重约3吨,体积约12立方米。它共装备了10个科学探测仪器,这些仪器能分析彗星的物理和化学构成及其电磁、引力特性。   “67P”诞生于46亿年前太阳系形成初期。与地球上地质变化频繁不同,彗星内部变化很少,好似一个飞行的“冰箱”,可能保存着太阳系诞生时最原始的物质。因此,对彗星的研究有助于揭开太阳系形成的诸多奥秘。   12年漫漫“追星”之旅终于成功画上句号,“罗塞塔”到底追到了什么?   ――给彗核拍照   彗星分为彗核、彗发、彗尾三部分,其中彗核通常被认为是彗星中心的固体部分。“罗塞塔”对“67P”的研究成果显示,其彗核整体形状呈现“双瓣”结构,包括较小的“头”、较大的“身”和连接两部分的“脖子”。在“罗塞塔”拍摄的高清图片上,可以见到“脖子”上横着一条约500米长的清晰的裂缝。   “罗塞塔”对约70%的彗核表面拍照,其余看不见的部分位于彗星南半球。已成像区域可划分为5种地质形态:尘埃覆盖区域、岩石样表面区域、带有小型坑状结构和环形结构的区域、大型洼地和平滑地带区域。多样的地质形态出人意料,因为一般认为彗星各个部分大体上由同种材料构成,表面地质形态应大致相同。   照片还显示“67P”表面存在着沙丘波纹状结构,有些石头后面还被“吹”出了风尾,可彗星并不像地球那样有风。研究人员认为,这可能是因为彗星在受热时冰挥发形成大气或彗发,尘埃也随着气体逃逸,但速度不够快又落回彗星表面,形成了这些特殊的地质特征。   ――否定磁场存在   “罗塞塔”观测结果显示“67P”上并没有磁场,这或许会让科学家重新认识太阳系构成。此前发现的月球岩石样本以及陨石上都探测到较强的磁场,而“67P”上竟然没有探测到一点磁场的迹象,这让人惊讶。   此前有观点认为,如果彗星上有磁场,或许能解释其构成物质在太阳系形成初期如何聚集到一起,这次在目标彗星上的新发现则显示上述观点可能并不成立。   ――发现多种有机化合物   2014年,“罗塞塔”携带的“菲莱”着陆器成功登陆“67P”,这也是首个在彗星上软着陆的人造探测器。   “菲莱”在“67P”表面的尘埃中发现了多种有机化合物,初步分析显示共有16种。其中,乙醛、甲胺等有机化合物在其他彗星上也曾发现过,但乙酰胺、异氰酸甲酯、丙醛和丙酮这4种有机化合物是首次发现。   此外,本次发现的16种化合物中有水、一氧化碳和甲烷,却不包括二氧化碳和氨。二氧化碳是彗星冰的主要成分之一,氨则是含氮化合物的原材料。研究人员本以为彗星表面尘埃中肯定会存在这两种分子,却没有发现,原因可能是在“菲莱”着陆的地区二氧化碳和氨早已蒸发。   ――探测到氧分子   “罗塞塔”探测器还首次在“67P”的彗核周围气体中探测到氧分子,这将帮助人类更好地理解太阳系的形成过程。彗核释放出的气体蒸发物又称彗发,主要由水、一氧化碳和二氧化碳组成。尽管科学家曾证明木星和土星上存在氧,但它此前从未在彗星上被发现。   此外,在“罗塞塔”环绕“67P”共同飞行的过程中,彗发中的氧分子和水分子的比例一直保持稳定,并未因彗星与太阳之间距离缩短或探测器轨道变化等原因发生变化。   鉴于彗发中氧分子的高含量和其与水分子比例的长期稳定,研究人员认为,彗星上的氧和水一样来自彗核,而且氧是在彗星形成初期就已融进了彗核。   ――发现“生命基石”   地球生命是怎么来的?有一种理论认为,是坠落到地球上的彗星带来了一些“生命基石”,这些物质在地球原始环境中互相作用,最终产生了生命。“罗塞塔”为这一假说提供了新的证据。   它发现,“67P”周围稀薄的气体中存在甘氨酸和磷元素。甘氨酸是一种氨基酸,而氨基酸在生物中发挥重要作用,被认为是“生命基石”。磷元素也广泛存在于脱氧核糖核酸(DNA)和细胞膜等处,有重要的生理作用。   2014年“罗塞塔”释放“菲莱”成功登陆彗核,时任欧航局局长让―雅克?多尔丹说,“我们雄心勃勃的‘罗塞塔’任务已在历史书上占据一席之地”。确实,这一彗星探测项目的成果刷新了人类对彗星的认识。 (责编:吴占桂、蒋成柳)相关的主题文章: