每日太空,为飞天梦想加油!
2007年06月25日太空资讯

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英国飞行员发现巨大不明飞行物

 

图注:鲍耶尔的描述与来自英国飞碟局的丹尼斯-普兰科特提供的照片极为相似。

    据英国《每日邮报》报道,英国奥尔德尼航空公司一架客机的机组人员和乘客在海峡群岛上空看到了可能是迄今为止最大的一个不明飞行物(UFO)。

    事情发生在几周前。50岁的机长雷-鲍耶尔首先发现了这个不明飞行物,他说是“一个雪茄形的发出强烈的炽白光的”物体。飞机进一步靠近,鲍耶尔透过双眼望远镜观察后说:“这是个非常尖锐的黄色物体,很薄,上面还有一块绿色区域。它固定在那里,比我们的高度高出2000英尺。

    开始我感觉距离我们大约10英里,后来我意识到可能要有40英里。大小上,我的第一感觉像一架波音737。实际上,它还要大的多,因为距离太远了。它应该有一英里宽。”

    客机继续向根西岛的方向前进,鲍耶尔发现在更往西的地方“还有一个同样的物体”。他说:“看起来非常像,但是要小一些,因为距离我们更远的原因。看上去它离根西岛的距离更近。我无法解释。大约有九分钟,我们可以清楚的看到这一切。我不确定这是不是来自另一个世界的东西。我所说的只是我飞行生涯中以前从未看到过的东西。”

    鲍耶尔的话得到了乘客凯特-罗塞尔和约翰-罗塞尔夫妇的证实。74岁的约翰说:“我看到一道橙色的光。就像一个拖长的椭圆形。”一位不愿透露姓名的蓝岛航空公司飞行员也证实了鲍耶尔的描述。

    英国民航局在安全通告中称,一架飞机在接近奥尔德尼时也发现了这个不明飞行物。来自民航局的消息人士称:“部分内容没有对外发布,我无法透露其中原因。”

阿特兰蒂斯号换地降落

美国“阿特兰蒂斯”号航天飞机于美国西部时间22日12时49分(北京时间23日凌晨3时49分)载着7名宇航员安全降落在加利福尼亚州爱德华兹空军基地。

    按照原计划,“阿特兰蒂斯”号应于21日在佛罗里达州肯尼迪航天中心着陆。

    由于佛罗里达州肯尼迪航天中心天气持续恶劣,美国宇航局临时决定让“阿特兰蒂斯”号改降加州爱德华兹空军基地。美国宇航局的统计数据显示,爱德华兹空军基地在此之前共曾降落过50架次航天飞机,最近一次是2005年“发现”号航天飞机降落在那里。

    美国宇航局发言人约翰逊说,“阿特兰蒂斯”号将在爱德华兹空军基地停留一周左右,然后“骑”在一架大型喷气飞机身上返回肯尼迪航天中心,美国宇航局将为此多花费170万美元。

月球液体望远镜取得大突破

没有大气,重力小,能排除人为干扰,月球是天文学家的理想观测地。科学家多年来梦想在月球上建造一种液体镜面望远镜,用反射液体旋转盘充当主镜。加拿大和美国科学家目前宣布在这一研究上取得重大突破,找到了能替代易在低温下凝固的水银,作为反射液体的材料.

加拿大拉瓦尔大学物理学家埃尔曼诺·博拉领导的加美两国科研队伍在21日出版的英国《自然》杂志上发表报告,宣布在月球液体镜面望远镜研究上取得技术突破。

    在月球上建立太空望远镜是天文学家长久以来的梦想。在没有大气和人为干扰的环境下,望远镜能更好捕捉到宇宙深处恒星的微弱光线。但是,望远镜的磨光镜片成本非常高昂,精确度要求很高。即使造成,还有如何把它搬运到月球上的问题。

    为了使月球观测成为事实,科学界很早开始设想在月球上建造一种液体镜面望远镜,用反射液体旋转盘充当望远镜主镜,既能降低成本,又能避免运输途中的危险。

    事实上,科学家已经在地球上建造过液体镜面望远镜,一般使用水银作为反射液体。他们说,成本只有传统大型望远镜的百分之一到百分之二。不过,如果想在月球上建造水银液体镜面望远镜,科学家面临一个难题:月球的低温会使水银变成固体。

    而博拉的科研团队正是在这一难题上取得重大突破。

  替代水银

    博拉说,他们找到一种能替代水银的反射液体材料,与水银相比,它们更不容易在低温下凝固。研究人员把一种防水溶剂ECOENG212加到液体铬里,然后把水银铺在液体铬上,得出的液体镜面质量“极为出色”,而且液体镜在持续数月的研究过程中始终保持稳定。

    缺憾之处在于,镜面反射性能还没有达到标准,溶剂凝固点虽已降至零下98摄氏度,而月球温度最低可能到零下130摄氏度。不过,科研人员认为,ECOENG212只是众多离子化合物中的一种,并不是唯一的溶剂选择。因此,他们对找到替代水银的最佳材料保持乐观态度。

    报告说:“至少还有100万种单一成分的离子性液体以及一万亿种三重成分的离子性液体,因此我们还有很多选择,足以找到最佳液体材料,尽量降低凝固点,提高稳定性。”科学家说,如果研制成功,月球液体镜面望远镜何时登月将部分取决于人类何时重返月球。

    报告说,小型月球液体镜面望远镜能够自动完成安装,像伞一样展开旋转盘。然而大型月球液体镜面望远镜不仅需要大量资金投入,还需要人工安装。

    也有一些人质疑这种月球望远镜还存在其他局限,因为液体镜面不能倾斜,因此只能从部分角度观察天空。观察者如果想追踪天空中某一物体的踪迹,用月球望远镜恐怕很难做到。

2007年06月19日太空资讯

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日本运行间谍卫星 违反公约监视全球

日本媒体日前报道,日本在联合国未作登记的情况下,有4颗间谍卫星已经在太空运行了4年,尽管日本曾签署了应向联合国报告所有间谍卫星的国际条约。

 

违反公约

 

根据1974年通过、1976年公布的《关于登记射入外层空间物体的公约》,签约国必须报告有关进入太空的人造卫星和其他物体的情况。

 

 

 

日本于1983年签署了该公约。

 

《日本时报》网站15日援引卫星的所有者、日本内阁卫星情报中心的一名官员的话报道:“出于安全原因,我们不能公开细节情况。”

 

观察全球

 

根据设计,4颗卫星共同组成日本的“全球情报处理系统”,2003年3月,该系统的首颗光学卫星和首颗雷达卫星顺利升空并投入使用。同年11月,H2A火箭6号固体燃料推进器出现故障,导致剩余2颗卫星发射失败。全球情报处理系统的第3颗卫星于2006年9月升空,最后一颗于今年2月24日发射上天。该系统的其中两颗卫星是光学卫星,其他两颗则是雷达卫星。这4颗卫星的功能结合在一起,日本就可能每天一次地监视地球上的任何角落。

 

据称,在日本完成间谍卫星计划的研究工作后,政府只披露说“轨道高度为400至600公里,卫星每4天回归原位”。

 

拒绝登记

 

《日本时报》的报道说,尽管日本的太空计划相对透明,而且在发射卫星时就公布了几乎所有相关信息。然而事实上,日本几乎没有披露关于这4颗间谍卫星的情况,这些卫星是通过H-2A火箭在2003年到2007年的数年间发射升空的。

 

迄今为止,日本只宣布了该系统4颗卫星发射成败情况,从未公开轨道的细节和卫星的照片。内阁卫星情报中心官员表示:“欧洲和美国的侦察卫星通常也不公布有关轨道的信息和照片,以隐藏(卫星的)侦测能力。”

 

这名官员同时强调:“本中心已经决定不在联合国登记这些卫星,即使这已经是公开的秘密,我们还是打算保留这个秘密。”

星惊现海岸线 三分之一表面曾为海洋

        据国外媒体报道,近日,有科学家表示,火星北部平原上长长的波状地貌可能是海岸线的遗迹,这意味着在至少20亿年前大洋覆盖了整个火星地表的三分之一。火星地质活动导致疑似海岸线变形。早在上个世纪80年代,海盗号太空船就拍到了这些绵延数千英里的海岸线。但美国宇航局火星全球探勘者号探测器在上个世纪90年代搜集到的地形数据显示,沿着这条可疑海岸线,存在巨大的、和山差不多大的高度变化,而一条海岸线相对海平面应该是一样的高度,这让人们对这些地形特征是否真的是一片消失已久的大洋海岸留下的痕迹产生了怀疑。但在《自然》杂志上发表论文的科学家们表示,火星极地的活动加上火星旋转轴在过去20亿到30亿年里差不多2000英里的活动引起了地表特征的变形,就像我们在这条可疑海岸线看到的。 美国行星科学家、这项研究的首席作者泰勒·佩纶在一次电话采访中说:“我们还没有直接确认火星上有海洋,因为那儿现在没有水。但火星极地的活动使得海岸线变形,这使我们排除了一个怀疑火星曾有海洋的重要原因。”其中一位研究人员,多伦多大学物理学家杰瑞·米特罗维卡表示,在某个时刻,火星上质量的一次巨大变化导致北极朝它现在的位置移动了50度,而火星方向的变化改变了这些海岸线的地形。

研究人员表示,这个海洋可能在火星前半段历史中曾覆盖了三分之一的火星地表,在至少20亿年前因为不明原因消失。佩纶说:“相对于火星的大小,这个海洋之于火星就如太平洋之于地球。”一部分水作为冰保留在火星两极,而且一些科学家认为还有更多的水保留在火星地下。除了对太阳系中的这颗地球的邻居增加了解之外,水的迹象对火星是否像我们认为的那样曾经有过生命体的问题来说也是至关重要的。米特罗维卡在一封电子邮件中说:“是否存在生命体的问题与是否有水这一点肯定是有关系的。所以,至少我们已经间接表明,火星上曾经有大量的水。”而前些年美国航空航天局发射的火星漫游者机遇号,发现了一系列火星上曾经存在液态水的证据。机遇号降落在火星Meridiani平原的一个小凹地内的。机遇号已经对其降落地周围的环境进行了探索,特别是对一块裸露出地面岩层上的一块岩石进行了研究。随着机遇号从岩石中获得更多的信息,火星曾经存在大量液态水的历史逐渐变的清晰了。美国航空航天局的科学家说:“液态水曾经冲刷过这些岩石,改变了它们的纹理,也改变了它们的化学成分。”根据机遇号的发现,有四条主要证据表明,火星表面曾经大量存在饱含矿物质的液态水。1,发现了镶嵌在岩石中的小的球状物体,这些凝结物是矿物质从水中凝结而形成的。2,在岩石不同角度有无规则的孔洞存在,这是有结晶从水中形成留下的痕迹。3,X-射线谱测量显示,岩石中含有大量硫,研究人员认为这是含硫酸盐水冲刷的结果。4,穆斯堡尔谱测量显示,在岩层中发现了黄钾铁矾,一种铁-硫酸盐水和物。这种物质在地球也存在,虽然很少,并且只能在有水的环境中形成。美国航空航天局科学家评论说:“我们相信在火星的这一地区,在某些时间,这里曾经是个适宜生命存在的环境。当然,我们说这里曾经是个适宜生命存在的环境,并不意味着那里曾存在过生命,我们不知道那里是否存在或生命。”但仍有许多重要问题,我们尚不能回答。如:“到底何时火星存在过液态水?”目前机遇号上的仪器无法确定这些岩石形成的年代,如果要做这样的实验,我们必须把这些岩石样品取回地球的实验室来做。

科学家已经将怀疑是古老海岸线的这两处地形命名为阿拉伯和德尤特罗尼鲁斯。火星地表长长的轮廓线稍稍上升然后下降,就像海浪一样。阿拉伯海岸线的高度改变了1.5英里,而德尤特罗尼鲁斯海岸线则变化了0.4英里。研究人员表示,火星的地理特征和地球的不尽相同,但是有科学家表示,也许火星也像地球一样,海洋和水的运动是随着两极以及太阳造成的引力而活动的,虽然这一想法完全是推测的,还没有得到严格的论证,但对于火星的秘密,迟早有一天人类都会掌握的。

欧航天局与美宇航局联手探索银河系起源

欧洲航天局与美国宇航局18日签署协议,将合作开发新一代太空望远镜“JWST”,并于2013年发射升空,以联手探索银河系的起源。

端午夜:苍穹上演“双星伴月”美丽天象

新华网天津6月18日电(记者周润健、蔡玉高)6月19日是一年一度的端午节。天津、江苏两地天文学会通报,当晚如果天气晴好,我国公众可欣赏到金星和土星“双星伴月”的迷人天象。

据天津市天文学会理事赵之珩介绍,19日20时左右,如果天晴气朗,人们可以在西偏南的低空一抹弯月的右上方看到明亮的土星,熠熠生辉。在土星的右上方3度处,是光芒四射的金星。在落日的余晖与彩霞中,金星、土星、弯月近距离齐争辉,美不胜收。有条件的公众如果借助天文望远镜欣赏,还能欣赏到土星迷人的草帽光环和金星的月牙儿形状。 继续阅读 »

端午节凌晨 新疆阿勒泰出现星月同辉奇观

2007年6月19日凌晨零时10分左右,新疆阿勒泰出现月星同辉奇观。 继续阅读 »

2007年06月17日太空资讯

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The United Nations Of Space

Countries used to race for space, now they collaborate. Since 1958, COSPAR – The Committee on Space Research – has played its part as the scientific United Nations of space research. Astrobiology Magazine talks to its president, Roger Bonnet, about COSPAR’s international role; its Panel on Planetary Protection, and the enforcement of their planetary protection rules for extra-terrestrial exploration.

Astrobiology Magazine: What is COSPAR?

Roger Bonnet: COSPAR is an institution that fosters communication between scientists of different countries. Currently COSPAR counts as members 44 countries; Egypt and Nigeria were the most recent countries to join.

These countries all send scientists to COSPAR meetings, but scientists from non-member countries can also participate in our big assemblies. We meet every two years in different parts of the world. Our last meeting was in July 2006 in Beijing and our next meeting will be in 2008 in Montreal.

AM: How is COSPAR structured and how does this structure relate to the field of astrobiology?

RB: COSPAR is divided into eight different commissions. The ones that relate to astrobiology are Commission E, which includes astronomy and astrophysics, Commission B, which deals with planets and the solar system, and Commission F, which is specific to the life sciences. We also have a Panel on Planetary Protection.

AM: How did COSPAR come into existence?

RB: The idea of creating an organization like COSPAR came over 50 years ago, just after the launch of the first Earth satellite, Sputnik 1. This event started the Space Era and was marked by a competition between the US and the Soviet Union to essentially dominate space, particularly military space.

It was clear that an scientific organization as independent as possible from politics and governments was needed. At the beginning there was a clear mandate for COSPAR to open the dialog between East Block scientists and scientists of the rest of the world, who were mainly from the US.

AM: Would you say that COSPAR functions as the United Nations of space research and collaboration?

RB: Yes, but with much less bureaucracy! So I guess that would make me the Kofi Annan of the scientific UN. (laughs)

AM:Aside from concerning itself with scientific issues, are there instances when political issues within the global space science community crop up which COSPAR is forced to address?

RB: Yes, because space is usually a big spender of money, particularly in the US, and when you spend a lot of money you immediately become political. But space research and exploration also are inherently political because of their high visibility.

These events include successes like landing a man on the Moon, or putting a probe on Titan. They also include failures like losing a satellite, or astronauts being killed during a mission. Fortunately these failures don’t happen very often, but the media tends to cover the failures more often than the successes.

COSPAR addresses some political initiatives like space exploration — for example, the new lunar program the President of the US announced a couple of years ago. At the last assembly in Beijing, we organized a round table discussion of all the space agencies attending to address this issue. NASA was present, ESA was present, and the other main space agencies of the world were present.

AM: When this new US exploration program called "Moon to Mars" was announced, was COSPAR consulted?

RB: No, but now COSPAR is involved because some scientists are asking us to organize an international collaboration to address the science that can be done within the framework of this initiative. China, India, Europe, the US, and Japan are all now planning missions to the Moon. When money is scarce it is better to join forces than to compete. It is logical that COSPAR would organize this cooperation from the scientific point of view in order to join the forces of the international community.

The scientists have proposed a scenario for cooperation, and this is now in the hands of the different space agencies. They will discuss amongst themselves whether or not they will accept the terms of this scenario. There is now an established dialogue.

AM: Since China is not politically in open dialogue with the US, is COSPAR fostering communication between the East and the West?

RB: Yes, but we are talking about scientific cooperation only, not political cooperation. I am acting as a mediator but only in trying to cope with the needs of the scientists. In 1982 an inter-agency working group for space science was established for cooperation between the US, Europe, Japan, and Russia in the exploration of Haley’s Comet. COSPAR acted as a triggering mechanism, and after that the agencies took over.

AM: Let’s turn now to recent news about water on Mars and the considerations and implications those findings bring to manned space exploration of that planet — in particular, with regard to planetary protection. What will COSPAR’s role be in trying to coordinate exploration around the mandate that planets be explored in the safest way possible in order to protect the environment?

RB: Well, water was found a long time ago on Mars. We knew liquid water existed on Mars in the past, and still may exist underground. What was discovered more recently was that water pored out of Mars within the last few years and has flowed down the sides of a crater. This is an absolutely fantastic discovery

AM: But they don’t know if the flow was liquid or ice?

RB: Perhaps it was some kind of permafrost, some kind of muddy consistency that flowed down. Whether it is more liquid or sublimated we don’t know. But it is a very important point that recently there has been some kind of material flowing from the slope of the crater which resembles water. It is stunning and marvelous!

AM: In light of this discovery, what is the onus now on COSPAR to encourage individual countries to take extra care with planetary protection measures?

RB: COSPAR has a special panel on planetary protection. John Rummel, who is now head of astrobiology at NASA , is the chairman. This panel has established some fundamental directives to prevent the export and transfer of terrestrial life, which would eliminate the possibility of finding pristine life on these bodies. Mars is clearly the planet where we send the largest number of spacecraft these days, and they have to go through the establishment of these rules and restrict the spacecraft to these rules.

AM: But not all spacecraft, including the most recent Mars rovers, were sent there under absolutely sterile conditions, were they?

RB: No, but you have several criteria which, depending upon the type of place you go or the science you do, one must adhere to. Some of them are sterilized to the point where the rules say they should be. If you send astronauts or you send samples for return missions to Mars and you bring materials back from Mars, you could contaminate the Earth with Martians!

If you plan to send human beings to Mars, which is the plan of Europe and the US several decades from now, you must be sure that they come back alive and not contaminated by strange organisms or diseases. So you must make sure that Mars is a completely sterile planet and that there is no danger of contamination.

If it is not a sterile planet, humans must analyze the forms of life which may have been discovered there, and determine whether or not they are dangerous for humankind. The problem is that on Mars, if life exists or has existed, it is most certainly not spread uniformly over the planet. There may be pockets of life here or there with nothing in between. So if you land in between and you don’t find anything, you cannot certify that life doesn’t exist on Mars.

One of the strategies is to find instrumentation, technologies, or approaches which would allow you to find the global distribution of life — like methane emissions or differences in surface temperature.

Nobody has any strong ideas on how to do this. But certainly having the global view on the distribution of the possible life forms on Mars is an important thing to address in the future. It is the role of COSPAR to organize symposia where these problems and issues are discussed.

AM: : Do you anticipate much dissent among the groups as to how to proceed? For instance, is there the possibility of a rogue agency acting out of line? And if so, could COSPAR pull them back into compliance?

RB: Certainly some of the planetary protection rules have become very expensive, so agencies have had a tendency to try to reduce the guidelines to make their implementation as cheap as possible, some to the point where they may no longer adhere to the rules.

But so far all the probes that have been sent have been sterilized to a certain degree. Mars Express and Beagle II (which crashed onto the surface of Mars) were sterilized according to the criteria established by COSPAR. But the agencies themselves are responsible for implementing that.

AM: So COSPAR can have influence but not ultimate enforcing power?

RB: No, we don’t have guns and bullets to enforce these things. We are not the Interpol of space agencies. But we certainly hope that we can help set standards by which all space agencies can agree to follow.

 

The Dwarf Planet Known As Eris Is More Massive Tha

Die-hard Pluto fans still seeking redemption for their demoted planet have cause for despair this week. New data shows that the dwarf planet Eris is 27 percent more massive than Pluto, thereby strengthening the decree last year that there are eight planets in the solar system and a growing list of dwarf planets.

According to Mike Brown, the discoverer of Eris, and his graduate student Emily Schaller, the data confirms that Eris weighs 16.6 billion trillion kilograms. They know this because of the time it takes Eris’s moon, Dysnomia, to complete an orbit.

"This was Pluto’s last chance to be the biggest thing found so far in the Kuiper belt," says Brown, a professor of planetary astronomy at the California Institute of Technology. "There was a possibility that Pluto and Eris were roughly the same size, but these new results show that it’s second place at best for Pluto."

Eris was discovered in 2005 with Palomar Observatory’s 48-inch Samuel Oschin Telescope, an instrument specially adapted to do comprehensive searches for objects in the sky.

When it became apparent that Eris was similar in size if not larger than Pluto, Brown and others called for the International Astronomical Union to rule on its planetary status. The end result was demotion of Pluto and the redesignation of it and other Kuiper-belt objects as dwarf planets.

Schaller says that the new results, obtained with Hubble Space Telescope and Keck Observatory data, indicate that the density of the material making up Eris is about two grams per cubic centimeter. This means that Eris very likely is made up of ice and rock, and thus is very similar in composition to Pluto. Past results from the Hubble Space Telescope had already allowed planetary scientists to determine that its diameter is 2,400 kilometers, also larger than Pluto’s.

"Pluto and Eris are essentially twins–except that Eris is slightly the pudgier of the two," says Brown. "And a little colder," adds Schaller.

The reason for Eris’s blustery surface conditions is its sheer distance from the sun. Currently 97 astronomical units from the sun (an astronomical unit being the distance between the sun and Earth), Eris hovers at temperatures well below 400 degrees Fahrenheit and is pretty dark.

However, things get a little better on Eris now and then. Orbiting the sun on a highly elliptical 560-year journey, Eris sweeps in as close to the sun as 38 astronomical units. But at present it is nearly as far away as it ever gets.

Pluto’s own elliptical orbit takes it as far away as 50 astronomical units from the sun during its 250-year revolution. This means that Eris is sometimes much closer to Earth than Pluto, although never closer than Neptune.

Based on spectral data, the researchers think Eris is covered with a layer of methane that has seeped from the interior and frozen on the surface. As in the case of Pluto, the methane has undergone chemical transformations, probably due to the faint solar radiation, causing the methane layer to redden. But the methane surface on Eris is somewhat more yellowish than the reddish-yellow surface of Pluto, perhaps because Eris is farther from the sun.

As for Dysnomia, the tiny satellite remains the only moon discovered orbiting Eris so far. Dysnomia is about 150 kilometers in diameter, is about 37,000 kilometers from Eris, and has a lunar "month" that lasts 16 days.

"But every year is 560 Earth-years," says Brown. "So on Eris they have a lot more months in their calendar."

Like the Earth-moon system, Eris-Dysnomia probably formed about 4.5 billion years ago following a massive collision.

Brown and Schaller are the authors of a paper, "The Mass of Dwarf Planet Eris," appearing in the June 15 issue of the journal Science.

The search for new planets and other bodies in the Kuiper belt is funded by Caltech and NASA. For more information on the program, see the Samuel Oschin Telescope’s website at http://www.astro.caltech.edu/palomarnew/sot.html.

 

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