破解太阳系形成之初的秘密

<正>星子慢慢从行星胚胎成长为行星而矮行星是没有长大的侏儒行星,是联系小行星和行星之间的纽带,"新视野"对冥王星的探测有助于揭示太阳系最初阶段行星形成的历史冥王星所在的柯伊伯带位于太阳系的边缘,寒冷而阴暗,探测难度很大这些遥远的冰冻天体究竟有何吸引力值得我们长期守候并努力探索呢?     

行星际超远距离飞行的“葵花宝典”——“新视野”冥王星探测任务分析

<正>迄今为止飞得最快的航天器、人类发射的第一个冥王星探测器"新视野"号,经过约9年的星际旅行,于2015年1月15日抵达距地球约47亿千米的冥王星附近,开始探测冥王星及其卫星、以及它们所处的柯伊伯带其他天体。虽然冥王星在2006年被开除出行星队伍,降级成为矮行星。这一方面使长期以来对冥王星是否具有行星地位的争议尘埃落定;另一方面,脱离了争议地位的冥王星却毫无争议     

2015年全球空间探测发展回顾

12015年空间探测成果概述 美国"新视野"探测器近距离飞越冥王星 2015年7月14日,美国"新视野"历经9年多、4.8×109km的深空飞行,首次近距离飞越了位于柯伊伯带的冥王星,最近距离约12472km,从而完成了太阳系除地球外原八大行星的探测,标志着人类行星际观测第一阶段任务的完成.     

太阳系探索的里程碑——“新视野”成功飞越冥王星

经过9.5年、4.8×1 09k m的长途跋涉,美国"新视野"(New Horizons)探测器于北京时间2015年7月14日19:49飞越太阳系最远的天体—冥王星(Pluto),最近距离约12472km,拍摄了太阳系原九大行星最后一块未开垦处女地的清晰照片,打开了人类的新视野,攀登上了太阳系天体探索的珠峰。"新视野"的这一瞥,不仅让人类终于看全了太阳系原九大行星的面目,更代表人类完成了太阳系观测"第一阶段"的任务。探测完冥王星及其卫星后,"新视野"将飞向太阳系外层的柯伊伯带(Kuiper Belt),那里可能隐藏着数以千计的冰冻岩石小天体,深藏着太阳系形成的秘密。"新视野"已成为探索太阳系的里程碑事件,其成果将使天文学家重新开始编写一本全新的教科书。藉此之际,本刊特推出"新视野"专题,以飨读者。     

新视野号飞掠“天涯海角”

<正>在美国诸多航天器里,"新视野号"绝对是排在前列的网红。它一路飞向太阳系的边缘,拍到了相当多遥远的天体。它的主要探测对象是被降格成矮行星的冥王星。这项任务已经在2015年顺利完成。不过"新视野号"的使命并没有结束。这也和矮行星这个定义有一定的关系,在冥王星所在的柯伊伯带里,有着大量小行星,冥王星不过是其中比较大的一个。那么其他柯伊伯带小行星是什么样的呢?在新年来临之际,"新视野号"近距离观测了其中一个,让天文学家们欣喜若狂,这就是Ultima Thule星。Ultima Thule星被众多媒体翻译为"天涯海角"。     

后冥王星时代“新视野”要去哪儿?

正2016年7月,美国航宇局(NASA)批准了"新视野"探测器的柯伊伯带扩展任务。在飞掠了冥王星之后,它又有了新的目标。随着冥王星在视场中越来越小,N A S A的"新视野"探测器也正在进入太阳系中一大片尚未被探测过的荒野之地,被称为柯伊伯带。这是一个位于气态巨行星海王星之外的冰封地带,包含有数十万个冰质小天体,被称为柯伊伯带天体,它们中有许多被     

走近冥王星的“新地平线”

<正>经过约9年的长途跋涉,美国研制的世界第一个冥王星探测器"新地平线"(New Horizons,又译"新视野"),于2015年1月15日开始探测位于太阳系边缘的冥王星及其卫星附近,触手探及太阳系最后一块未开垦的处女地,打开人类的新视野。目前,该探测器已飞行了约4.8×109km,距冥王星的路程仅剩2.2×108km。冥王星与地球的最近距离也有4.7×109km,最远100多亿千米,因此至今还没有一个空间探测器探测过它。探测完冥王星及其卫星后,它将飞向柯伊伯带(Kuiper Belt),去寻找关于太阳系起源和地球生命起源的线索。     

“新视野”:用5%的数据颠覆既有认识

正2015年7月14日,当美国航宇局(NASA)的一个探测器飞掠过这个遥远的星球时,它永远地改变了我们此前对这个神秘天体系统的认识。在我们太阳系中历经了9.5年距离达50亿千米的征程之后,NASA的"新视野"号探测器对冥王星及其卫星系统进行了探测。2015年7月14日,当它从冥王星表面上方12400千米处飞过时,则把这部史诗推向了高峰。"新视野"上所搭载的7台科学仪器成功地进行了超过1000次的独立观测。此     

“新视野”是深空探测的成功范例

<正>深空探测是指脱离地球引力场,进入太阳系空间和宇宙空间的探测。人类在深空探测方面,在已取得的一系列成果的基础上,正在迈向更远的太空。"新视野"是美国航宇局(NASA)在2000年开始设计的一个直达冥王星和柯伊柏带的深空探测器。因为它使用直线冲出太阳系的轨道,所以,只有中间利用了一次木星引力以增加速度。即便如此,"新视野"自从2006年1月19日发射至今,仍然花了长达9年半的时间,才在2015年7月14日,     

太阳系存在未知行星吗?

正由于柯伊柏带天体运行轨道与预期不符,有天文学家提出,太阳系内柯依伯带以远的区域内可能存在未知的大行星。由于这些区域又冷又暗,未知行星反射的太阳光极为微弱,要通过观测确证未知行星非常困难。但未知行星一旦确证,将改变太阳系的疆界,行星的定义可能又要重新修改,太阳系形成模型也要修改。深空探测将在发现大行星的过程中发挥关键作用。公众感兴趣的话题2016年1月20日,美国加州理     

The VESTA project: Combined studies of Mars and small bodies of the solar system

A mission to Mars and small solar system bodies is presently studied as a possible collaboration between INTERCOSMOS, CNES, ESA and eventually other participants. The VESTA concept, based on the same strategy as the successful VEGA mission, is more ambitious, as two spacecrafts separate soon after launch: a soviet spacecraft, dedicated to the study of Mars, and a spacecraft dedicated to the study of small bodies, under the responsibility of CNES and ESA. This spacecraft would use Mars gravity assists to visit up to 4 small bodies in less than 5 years. The mission is duplicated, which means that up to 8 small bodies could be studied (e.g. 6 main belt asteroids, 1 apollo-amor asteroid and 1 short period comet). Low relative velocities (< 3.5 km/s) should allow to drop a penetrator on two large main belt asteroids, such as 4 Vesta and 1 Ceres (1994 launch).     

深空探测太阳电池阵应用及关键技术分析

从1958年启动月球探测活动至今,经过几十年的发展,人类在深空探测领域取得重大成果。本文首先介绍地内行星、地外行星与登陆探测等领域探测器用太阳电池阵技术的应用情况,同时结合地内行星探测、地外行星探测与登陆探测任务所面临的不同空间环境特点对航天器太阳电池阵进行关键技术分析,梳理深空探测任务对太阳电池阵不同的技术需求及其所需解决的关键问题,从中得出未来深空探测太阳电池阵技术的趋势是将向更高效率太阳电池阵、环境自适应技术、高重量比功率、高体积比功率的方向发展。     

The magnetic fields of Jupiter and Saturn

Jupiter and Saturn are two of the more “exotic” planets in our solar system. The former possesses its own system with 15 satellites in orbit about the parent planet. Saturn has a uniquely well developed and distinctive ring system of particulate matter and also at least 11 satellites, including the largest one amongst all the planets, Titan, with a radius of 2900 km ± 100 km. In the decade of the 70's, the USA launched 4 unmanned spacecraft to probe these giant planets in-situ with a suite of highly advanced instrumentation. Four separate encounters have occurred at Jupiter: 1. Pioneer 10 in December 1973 2. Pioner 11 in December 1974 3. Voyager 1 in March 1979 4. Voyager 2 in July 1979 The characteristics of these trajectories is shown in Table I. Thus far, only a single encounter of Saturn has occurred, that by Pioneer 11 in September 1979. Future encounters of Saturn by Voyager spacecraft will occur in mid-November 1980 and late-August 1981. It is the purpose of this talk to summarize what is presently known about the magnetic fields of these planets and the characteristics of their magnetospheres, which are formed by interaction with the solar wind.     

Deep space environments for human exploration.

Mission scenarios outside the Earth's protective magnetic shield are being studied. Included are high usage assets in the near-Earth environment for casual trips, for research, and for commercial/operational platforms, in which career exposures will be multi-mission determined over the astronaut's lifetime. The operational platforms will serve as launching points for deep space exploration missions, characterized by a single long-duration mission during the astronaut's career. The exploration beyond these operational platforms will include missions to planets, asteroids, and planetary satellites. The interplanetary environment is evaluated using convective diffusion theory. Local environments for each celestial body are modeled by using results from the most recent targeted spacecraft, and integrated into the design environments. Design scenarios are then evaluated for these missions. The underlying assumptions in arriving at the model environments and their impact on mission exposures within various shield materials will be discussed.     

China's Future Missions for Deep Space Exploration and Exoplanet Space Survey by 2030

Four future missions for deep space exploration and future space-based exoplanet surveys on habitable planets by 2030 are scheduled to be launched. Two Mars exploration missions are designed to investigate geological structure, the material on Martian surface, and retrieve returned samples. The asteroids and main belt comet exploration is expected to explore two objects within 10 years. The small-body mission will aim to land on the asteroid and get samples return to Earth. The basic physical characteristics of the two objects will be obtained through the mission. The exploration of Jupiter system will characterize the environment of Jupiter and the four largest Moons and understand the atmosphere of Jupiter. In addition, we further introduce two space-based exoplanet survey by 2030, Miyin Program and Closeby Habitable Exoplanet Survey (CHES Mission). Miyin program aims to detect habitable exoplanets using interferometry, while CHES mission expects to discover habitable exoplanets orbiting FGK stars within 10 pc through astrometry. The above-mentioned missions are positively to achieve breakthroughs in the field of planetary science.      

Physical study of outer belt asteroids

Located in the proximity of Jovian resonances, the outer belt asteroids are kept from interacting with other asteroids and are likely to represent a population of primitive bodies. The systematic investigation of the physical properties of these objects and the subsequent understanding of their nature and origin, will have a direct implication for any theoretical study on the evolution of the solar system. In the last decade the information on the spectral and photometric properties of distant asteroids has strongly increased, leading to the formulation of specific questions, the answer to which will enable a comprehensive picture of this class of bodies. Since 1988 our group is carrying out a program devoted to the physical study of the Trojans and outer belt asteroids (Hilda and Cybele groups) to characterize their rotational properties, composition and shapes. During several observing campaigns, carried out at different observatories, reliable rotational periods and light curve amplitudes have been determined for eight distant asteroids using both CCD and photoelectric photometry. We will here present some preliminary results of our campaigns.     

New results on planetary lightning

We present the latest observations from spacecraft and ground-based instruments in search for lightning activity in the atmospheres of planets in the solar system, and put them in context of previous research. Since the comprehensive book on planetary atmospheric electricity compiled by Leblanc et al. (2008), advances in remote sensing technology and telescopic optics enable detection of additional and new electromagnetic and optical emissions, respectively. Orbiting spacecraft such as Mars Express, Venus Express and Cassini yield new results, and we highlight the giant storm on Saturn of 2010/2011 that was probably the single most powerful thunderstorm ever observed in the solar system. We also describe theoretical models, laboratory spark experiments simulating conditions in planetary mixtures and map open issues.     

The interstellar heliopause probe technology reference study

The interstellar heliopause probe (IHP) is one of ESA’s technology reference studies (TRS). The TRS aim to focus the development of strategically important technologies of relevance to future science missions by studying technologically demanding and scientifically interesting missions that are currently not part of the science mission programme.

Equipped with a highly integrated payload suite (HIPS), the IHP will perform in situ exploration of the heliopause and the heliospheric interface. The HIPS, which is a standard element in all TRSs, miniaturize payloads through resource reduction by using miniaturized components and sensors, and by sharing common structures and payload functionality.

To achieve the scientific requirements of the mission, the spacecraft is to leave the heliosphere as close to the heliosphere nose as possible and reach a distance of 200 AU from the Sun within 25 years. This is possible by using a trajectory with two solar flybys and a solar sail with characteristic acceleration of 1.1 mm/s², which corresponds to a 245 × 245 m² solar sail and a sail thickness of 1–2 μm. The trajectory facilitates a modest sail design that could potentially be developed in a reasonable timeframe.

In this paper, an update to the results of studies being performed on this mission will be given and the current mission baseline and spacecraft design will be described. Furthermore, alternative solar sail systems and enabling technologies will be discussed.     

The search for extra-solar planetary systems.

I review the observational evidence for planetary systems around nearby stars and, using our own solar system as a guide, assess the stringent requirements that new searches need to meet in order to unambiguously establish the presence of another planetary system. Basically, these requirements are: 1 milliarcsecond or better positional accuracy for astrometric techniques, 9 orders of magnitude or better star to planet luminosity ratio discrimination at 0.5 to 1" separation in the optical for direct imaging techniques, 10 meters sec-1 or better radial velocity accuracy for reflex motion techniques and +/-1% or better brightness fluctuation accuracy for planet/star occultation measurements. The astrometric accuracy is in reach of HST, direct imaging will require much larger telescopes and/or a 50 times smoother mirror than HST while the reflex motion and occultation techniques best performed on the ground are just becoming viable and promise exciting new discoveries. On the other band, new indirect evidence on the existence of other planetary systems also comes from the observation of large dusty disks around nearby main sequence stars not too dissimilar from our sun. In one particular case, that of Beta Pictoris, a flattened disk seen nearly edge-on has been imaged in the optical and near IR down to almost 70 AU of the star. It probably represents a young planetary system in its clearing out phase as planetesimals collide, erode and are swept out of the inner system by radiation pressure. The hypothesized Kuiper belt around our solar system may be the analogous structure in a later evolutionary stage. Features of this type have been detected in the far IR and sub-millimeter wavelength regions around 50-100 nearby main sequence and pre-main sequence stars. I discuss a battery of new accurate observations planned in the near future of these objects some of which may actually harbour planets or planetesimals that will certainly dramatically improve our knowledge of planetary system formation processes and our peculiar position in this scheme.     

December 2006 solar extreme events and their influence on the near-Earth space environment: “Universitetskiy-Tatiana” satellite observations

The Russian microsatellite “Universitetskiy-Tatiana” was launched on Jan. 20, 2005 and was both a scientific and educational mission. Its two main aims were declared as: (1) monitoring of the energetic particles dynamics in the near-Earth space environment after solar events and during quiet times, (2) educational activities based on experimental data obtained from the spacecraft. In this paper observations acquired during Dec. 5–16, 2006, known as “Solar Extreme Events 2006”, were analyzed. The “Universitetskiy-Tatiana” microsatellite orbit permits one to measure both solar energetic particle dynamics, variations of the boundary of solar particle penetration, as well as relativistic and sub-relativistic electrons of the Earth’s outer radiation belt during and after magnetic storms. Both relativistic electrons of the Earth’s outer radiation and solar energetic particles are an important source of radiation damage in near-Earth space. Therefore, the presented experimental results demonstrate the successful application of a small educational spacecraft both for scientific and educational programs.