首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
太阳系探索和地外生命搜索   总被引:1,自引:0,他引:1  
综述了国际上进行太阳系空间探测的现状,着重介绍了探测月球,火星,不星和外行星的意义,目的,手段和成就,择要介绍了美国宇般局,欧洲空间局,俄罗斯和日本近年来和下世纪初的空间计划,论及地外生命搜索,主要介绍了火星上水和生命搜索进展,地外生命搜索的的SETI计划及其发民菜,物理学家与生物学家有关搜索成功的可能性的争论,以及太阳系外行星系统的发现,太阳系外行星系统的发现是当代天文学最时髦的,也将是未来21世纪成果最丰富的研究领域之一,目前,已经发现了大约50个太阳系外行星系统,太阳系外行星系统的发现与地外生命搜索研究是密不可分的,这项研究近20年来发展较快,它的研究也促进了航天学,宇宙化学,天文生物学乃至哲学等其化学科的发展。  相似文献   

2.
2016年,行星科学家发现恒星TRAPPIST-1拥有7颗地球大小的岩石行星,其中3颗位于宜居带中。最近,费德里科·弗拉切蒂(Federico Fraschetti)和来自哈佛大学史密森天体物理中心(Harvard & Smithsonian)的研究团队首次计算出高能粒子撞击行星的强度.  相似文献   

3.
地球之外存在生命吗?有三条途径可以来寻找它们。宇宙中有多少生命?它们会具有什么样的形式?这些科学中最大的谜题一直萦绕着人类。单就层出不穷的外星生命科幻电影来看,对地外生命的兴趣绝非仅限于科学家。  相似文献   

4.
几个世纪以来。科学家们一直想弄清楚,在我们居住的地球之外是否还有其他的生命。人类发射的探测器在月球、火星和金星上登陆。希望能找到一些原始的生命形式。但至今仍然一无所获。天文学家用巨大的射电望远镜监听宇宙中智慧生命发出的信号。但是宇宙里一片寂静。  相似文献   

5.
问天 《天文爱好者》2014,(10):42-46
根据太阳系行星物质的主要性态和大小,人们通常将其分成行星(包括类地行星和类木行星)、卫星、小行星、彗星和流星体。类地行星包括水星、金星、地球和火星;类木行星包括木星、土星、天王星和海王星;质量较大的小行星和卫星的内部结构与类地行星相似,质量较小的小行星和卫星以及流星体主要由岩石和金属组成;彗星是含有太阳系形成时期物质且没有经过太多物理和化学演化的冰态小天体。  相似文献   

6.
刘玉娟  赵刚 《天文学进展》2005,23(3):226-238
随着对外太空探索脚步的加快,人类开始对与太阳系具有相似结构的恒星行星系统越来越感兴趣,因为它们有可能也拥有智慧生命。简单介绍了目前地外恒星行星系统的探测情况,分析了现在比较常用的几种探测方法的可行性和适用范围,重点讨论了利用视向速度法得到的结果及其意义。近年来,各种探索地外行星的小卫星的升空以及探测技术的进步使得大批高质量数据获得成为可能。可以预见,在未来几年内,地外恒星行星系统的探索将会进入一个蓬勃发展阶段。  相似文献   

7.
生命的本源是什么?我们从哪里来,又将到哪里去?这类所谓“终极问题”,经常困扰着我们。科学、宗教,对这些问题有不同的解释,而在科幻界,拟或奇幻界,则有一些人,对这些问题给出了更有趣、更大胆的解释。这次,要给大家介绍的这部影片,就对生命的本源,以及生命和行星的关系,给出了一个很奇特的解释。这个解释看起来纯属天方夜谭,但至少,它对我们拓展思维有很大的好处。  相似文献   

8.
月上中秋节,莹莹如宝鉴。皓夜茫无边,五星亦可见。无论是皎洁的满月还是明亮的行星,它们自身都并不发光,我们之所以能够看见它们,是因为它们反射了来自太阳的光——确切地说,是反射了太阳光中的一部分。  相似文献   

9.
2011年4月17日,看中央9频道中播放的《太阳系的奇迹》系列节目(译自2010年3月发行的BBC Wonders of The Solar System)。在第5集中,理查德·胡佛(Richard Hoover)博士作为专家来讲解外星生命内容。  相似文献   

10.
问天 《天文爱好者》2014,(12):46-52
小行星与慧星研究 小行星和彗星是45亿年前太阳系形成时遗留的原始残骸,包含着太阳系早期的物理和化学信息,对研究太阳系起源和行星系统形成具有重要科学意义,同时精密确定其轨道动力学演化又是目前空间环境和地球安全方面的重要现实需求。  相似文献   

11.
本文简要地介绍了目前太阳系外行星系统动力演化的研究现状。我们用数值模拟方法和并从分析的角度研究了GJ 876和HD 82 943。通过分析不同的共面和非共面构型 ,我们发现所有的稳定轨道都和2 :1共振有关 ,此外我们还发现在这两个系统内存在近星点共振—对应了两个行星的近星点经度之差在1 80 0或者 0 0附近秤动。这两种机制对维持行星系统的稳定性起了重要作用。  相似文献   

12.
The WASP project and infrastructure supporting the SuperWASP Facility are described. As the instrument, reduction pipeline and archive system are now fully operative we expect the system to have a major impact in the discovery of bright exo-planet candidates as well in more general variable star projects.  相似文献   

13.
We review the methodology of searches for planet-mass bodies around neutron stars observable as radio pulsars and discuss the current status of these searches. PSR B1257 + 12, a 6.2-millisecond pulsar, remains the only neutron star accompanied by confirmed planets. It is possible that there is a fourth distant planet in the 1257+12 system. The best of the other candidates for pulsar planets under consideration is a distant, possibly Jovian-mass companion to PSR B1620-26, a 11-millisecond pulsar in the globular cluster M4. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

14.
A full understanding of the properties of substellar objects is one of the major challenges facing astrophysics. Since their discovery in 1995, hundreds of brown dwarfs and extrasolar planets have been discovered. While these discoveries have enabled important comparisons with theory, observational progress has been much more rapid than the theoretical understanding of cool atmospheres. The reliable determination of mass, abundances, gravities and temperatures is not yet possible. The key problem is that substellar objects emit their observable radiation in the infrared region of the spectrum where our knowledge of atomic, molecular and line broadening data is poor. Here we report on the status of our PoSSO (Physics of SubStellar Objects) project. In order to understand brown dwarfs and extrasolar planets increasing more like those in our solar system, we are studying a wide range of processes. Here we give an update on the project and sketch an outline of atoms, molecules and processes requiring study. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

15.
16.
It is shown that the planetary distances of the Solar System are distributed according to the L 0 resonance, where L 0 = cP 0 = 19.24 a.u. is the wavelength of the “cosmological oscillation” of the Universe (whose nature is unknown). Here, c is the speed of light and P 0 = 160 min is the period of pulsations of the Sun and the Universe, which turned out to be equal to 1/9 of the mean terrestrial day. Exoplanets do not exhibit the L 0 resonance; instead, they demonstrate on average a spatial resonance on a scale of 14.8 a.u., pointing to a mechanism of formation of exoplanetary systems which differs from the commonly accepted one (by the capture of “mesoplanets,” rather than from near-star nebulae). This indicates that the L 0 resonance is a specific feature just of the Solar System. The L 0 (P 0) aspect of the anthropic principle, realized only near the Sun, distinguishes our planetary system from a number of observed exoplanetary systems. This fact makes the anthropic principle in its strong formulation more evident, localizing its effectiveness. Probably, it is closely related to the appearance of life on the Earth, which unexpectedly, sadly, and charmingly makes any talks on extraterrestrial civilizations devoid of any prospect.  相似文献   

17.
傅燕宁  黄天衣 《天文学报》1995,36(1):93-100
以JPL提供的太阳系天体数值历表DE200/LE200和美国海军天文台提供的岁差、章动改正程序为出发点,本文介绍预报大行星、月球掩源的一种方法,本方法分三个步骤:首先给出被掩源所满足的必要条件,并据此进行被掩源的初选;其次预报掩事件的全局情况,即掩发生的始终时刻和比较精确的地球椭球表面上可观测区域边界,在可观测区域边界中,本文发现了文献中未见出现过的出没南北界最后;预报地方见掩情况。  相似文献   

18.
Analysis of the data obtained during transits of low-orbit extrasolar planets across the stellar disk yields different estimates of their atmospheric loss rates. Experimental data point to the probable existence of several distinct subtypes of extrasolar giant planets, including “hot Jupiters” of low density (HD 209458b), with massive cores composed of heavy elements (HD 149026b), and others. We show that the expected hot-Jupiter mass losses due to atmospheric escape on a cosmogonic time scale do not exceed a few percent, while the losses through Jeans dissipation are negligible. We also argue that low-orbit giant planets should have a strong magnetic field that interacts with circumstellar plasma with the planet’s supersonic orbital velocity. The magnetic field properties can be used to search for extrasolar planets.  相似文献   

19.
Viorel Badescu 《Icarus》2011,216(2):485-491
Bodies with water, ammonia or ethane oceans are possible in interstellar space. This may happen for optically thick atmospheres of methane, ethane and carbon dioxide.  相似文献   

20.
Spectroscopic studies of stars with and without planetary systems have concluded that planet hosts are more metal‐rich. This enrichment is also seen in the other chemical elements studied and is likely to be primordial in nature. Interesting trends of different chemical elements begin to appear as the number of extrasolar planets continues to grow. I present our current knowledge concerning the observed abundance trends of chemical elements in planet hosts and their possible implications. In most cases the abundance trends of planet host stars are identical to those of the comparison sample. However, some exceptions (such as Li) have been reported too. No clear correlation was found between orbital parameters of planets and host star metallicity. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号