共查询到19条相似文献，搜索用时 140 毫秒
1.
制约卫星轨道寿命的另一种机制(续) 总被引：2，自引：0，他引：2
对于制约低轨人造地球卫星轨道寿命的耗散机制，人们已有足够的重视，但在深空探测中，另一种制约低轨卫星轨道寿命的引力机制同样应予重视，前文讨论了高轨卫星的情况，在第三体引力作用下，有可能导致卫星轨道偏心率产生变幅较大的长周期变化。特别是极轨卫星，其轨道偏心率在一定的时间内可增大到使其近星距rp=a(1-e)≈Re（Re是中心天体的赤道半径），从而落到中心天体上，结束其轨道寿命，目前对低轨卫星作了详尽的理论分析，研究表明，与高轨卫星有类似结果，但其力学机制却不相同，低轨卫星的轨道寿命与第三体引力无关。它取决于中心天体非球形引力位中的扁率项（即J2项）与其他带谐项之间的相对大小，这不仅是一个纯理论结果，也有实际背景，在太阳系中慢自传天体（月球和金星等）的低轨卫星就存在这一问题，还给出了有关判据，并以计算实例作了验证。 相似文献
2.
天体自转因素导致的相对论性效应 总被引：1，自引：0，他引：1
韩韬 《紫金山天文台台刊》1991,(4)
本文在PPN框架中得到了太用系内自转因素产生的瞬时轨道根数改正的一阶封闭分析解.轨道半长径和偏心率不受长期效应的影响,只受周期效应的影响;轨道倾角、升交点经度、近星点角距,平近点角既受长期效应又受周期效应的影响.我们用两种引力理论分别计算了太阳自转对地内大行星及—些小行星轨道,行星自转对自然卫星轨道,地球自转对人造卫星轨道所产生的各相对论性效应. 相似文献
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4.
轨道偏心率的变化极其重要,它是制约各类(不同高度)空间飞行体轨道寿命的关键因素之一.对于地球低轨卫星,主要受大气耗散作用的影响,而对环月(或环火星)低轨卫星,主要受非球形引力位中奇次带谐项的影响,会出现变幅较大的长周期变化,从而导致近星点高度hp在一段时间内有明显的下降趋势.对大偏心率轨道和高轨道,第三体的引力作用也会使e出现变幅较大的长周期变化,近星点高度hp也会有明显下降的现象,这都会影响卫星的轨道寿命,但这一动力学机制与大气耗散机制和非球形引力机制都不相同.即对轨道偏心率的变化特征及其对轨道寿命的影响作一综述. 相似文献
5.
6月3日月球距地球最近 月球是地球的天然卫星,它沿着一椭圆轨道围绕地球公转,轨道的偏心率为0.0549,月球距地球最近(近地点)时平均距离为363300千米,远地点的平均距离为405500千米。6月3日21时月球距地球的距离最近,为357240千米,是本年中距离最近的一次。从地球看去月球的视直径为33′27″。6月3日12时20 相似文献
6.
月球物理天平动对环月轨道器运动的影响 总被引：3，自引：0，他引：3
月球物理天平动是月球赤道在空间真实的摆动，会导致月球引力场在空间坐标系中的变化，从而引起环月轨道器(以下称为月球卫星)的轨道变化，这与地球的岁差章动现象对地球卫星轨道的影响类似．采用类似对地球岁差章动的处理方法，讨论月球物理天平动对月球卫星轨道的影响，给出相应的引力位的变化及卫星轨道的摄动解，清楚地表明了月球卫星轨道的变化规律，并和数值解进行了比对，从定性和定量方面作一讨论． 相似文献
7.
傅燕宁 《紫金山天文台台刊》1995,14(2):110-119
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,本文介绍为计算大行星、月球掩源(恒星或射电源)而进行的被掩源初选的一种有效方法。用该法本文给出了1995-2050年各大行星及月球可能掩的FK5星。 相似文献
8.
偏心率是描述天体运动轨道的重要参数之一, 能够为揭示天体的动力学演化提供重要线索, 进而帮助理解天体形成与演化的过程及背后的物理机制. 随着天文观测技术的不断发展, 人们对于天体运动轨道的研究已经走出太阳系, 包含的系统也从大质量端的恒星系统延伸到了低质量端的行星系统. 聚焦天体轨道偏心率研究, 回顾了目前在恒星系统(包括主序恒星、褐矮星以及致密星)和行星系统(包括太阳系外巨行星以及``超级地球''、``亚海王星''等小质量系外行星)方面取得的进展, 总结了不同尺度结构下偏心率研究的一些共同之处和待解决的问题. 并结合当下和未来的相关天文观测设备和项目, 对未来天体轨道偏心率方面的研究工作进行了展望. 相似文献
9.
地球磁场对带电人造卫星轨道根数的摄动影响 总被引：2，自引：0，他引：2
研究了地球磁场对带电的非赤道卫星的轨道根数的摄动影响，理论结果表明，地球磁场对带电卫星的轨道半长轴没有摄动影响，既无周期摄动，也无长期摄动，但对轨道偏心率、轨道倾角、升交点赤经、近地点经度和历元平近点角均有周期摄动，且对升交点和近地点经度还有长期摄动效应，通过算例表明，当卫星带有大量电菏时，地球磁场对卫星轨道的摄动影响必须加以考虑。 相似文献
10.
研究了地球磁场对带电的非赤道卫星的轨道根数的摄动影响。理论结果表明，地球磁场对带电卫星的轨道半长轴没有摄动影响，既无周期摄动，也无长期摄动，但对轨道偏心率、轨道倾角、升交点赤经、近地点经度和历元平近点角均有周期摄动，且对升交点和近地点经度还有长期摄动效应。通过算例表明，当卫星带有大量电荷时，地球磁场对卫星轨道的摄动影响必须加以考虑。 相似文献
11.
Apsidal resonance causes long periodic variation of large amplitude in the eccentricity of the minor bodies of the solar system (asteroids, natural satellites, artificial satellites of the planets and the moon). Especially for a large-inclination orbiting satellite the increased eccentricity may cause its pericentric distance to decrease below the radius of the primary. This effect, completely different from the dissipative effect of the earth's atmosphere, will be analysed theoretically and illustrated with numerical examples in this paper. 相似文献
12.
L. G. Lukyanov 《Solar System Research》2011,45(1):75-79
The convergence of Lagrange series is studied on a part of the elliptical orbit for values of eccentricity exceeding the Laplace
limit. The regions in the vicinity of the two apses of the orbit are identified in which the Lagrange series converge absolutely
and uniformly for the values of the eccentricity greater than the Laplace limit. The obtained results are of practical interest
for astronomy when studying motions of stellar bodies in orbits with high eccentricity. In particular, these series may be
used to calculate the orbits of comets or asteroids with high eccentricity as they pass through the neighborhood of perihelion
or to calculate the orbits of artificial satellites with high eccentricity “hanging” in the vicinity of apogee. In stellar
dynamics, these series may be used in cases of close binary stars, many of which move in orbits with an eccentricity greater
than the Laplace limit. 相似文献
13.
Using recently published determinations of the diameters and orbital elements of the uranian satellites and assuming reasonable dissipation functions and rigidities for icy satellites, the eccentricity decay times for the satellites were calculated. For the inner three, decay times are on the order of 107–108 years, making it difficult to understand why these satellites still have their observed eccentricities. The three inner satellites have a near-commensurability in their mean motions that may be able to force their eccentricities at some time in the future, but cannot force them now. Several possible explanations exist: (1) The reported eccentricities are incorrect, and are in fact near-zero. (2) The reported mean motions are incorrect, and an exact commensurability exists. (3) The physical properties that we have assumed for the satellites are grossly in error (e.g., dissipation function Q is in reality very large). (4) The system is evolving very rapidly, perhaps from a previous state of higher eccentricity. Cases 1 and 2 are unlikely when one considers the quality of existing data. Case 3 would be more consistent with non-icy compositions. Cases 2 and 4 would imply some tidal heating of the satellites, particularly Ariel. A new lower bound of ～ 1.7 × 104 on the Q of Uranus is calculated from the mass of Ariel and its proximity to Uranus. 相似文献
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15.
O. C. Winter L. A. G. Boldrin E. Vieira Neto R. Vieira Martins S. M. Giuliatti Winter R. S. Gomes F. Marchis P. Descamps 《Monthly notices of the Royal Astronomical Society》2009,395(1):218-227
The triple asteroidal system (87) Sylvia is composed of a 280-km primary and two small moonlets named Romulus and Remus ( Marchis et al. 2005b ). Sylvia is located in the main asteroid belt, with semi-major axis of about 3.49 au, eccentricity of 0.08 and 11° of orbital inclination. The satellites are in nearly equatorial circular orbits around the primary, with orbital radius of about 1360 km (Romulus) and 710 km (Remus). In this work, we study the stability of the satellites Romulus and Remus. In order to identify the effects and the contribution of each perturber, we performed numerical simulations considering a set of different systems. The results from the three-body problem, Sylvia–Romulus–Remus, show no significant variation of their orbital elements. However, the inclinations of the satellites present a long-period evolution with amplitude of about 20° when the Sun is included in the system. Such amplitude is amplified to more than 50° when Jupiter is included. These evolutions are very similar for both satellites. An analysis of these results shows that Romulus and Remus are librating in a secular resonance and their longitude of the nodes are locked to each other. Further simulations show that the amplitude of oscillation of the satellites' inclination can reach higher values depending on the initial values of their longitude of pericentre. In those cases, the satellites get caught in an evection resonance with Jupiter, their eccentricities grow and they eventually collide with Sylvia. However, the orbital evolutions of the satellites became completely stable when the oblateness of Sylvia is included in the simulations. The value of Sylvia's J 2 is about 0.17, which is very high. However, even just 0.1 per cent of this value is enough to keep the satellite's orbital elements with no significant variation. 相似文献
16.
This paper presents a computer investigation extending to the case of parabolic orbits, an earlier investigation conducted by Barricelli and Metcalfe (1969) on lunar impacts by external low eccentricity satellites as a means to interpret the asymmetric distribution of lunar maria. Parabolic orbits can be approximated by two kinds of objects:
- High eccentricity external satellites may, near periapsis, approach the Moon with orbital velocity and other characteristics closely resembling those of a parabolic orbit.
- Asteroids and meteoroids approaching the Earth-Moon system with a low velocity may have moved in a nearly parabolic orbit when they reached the lunar distance from the Earth at the time when the impacts which carved the lunar maria took place.
17.
The effect of solar pressure on the two-dimensional motion of two cable-connected satellites in the Earth's central gravitational field of force for the elliptical orbit of the centre-of-mass of the system has been analysed. The equations of motion obtianed are nonlinear and non-autonomous.It is concluded with the aid of non-resonant solution that the system experiences resonance main as well as parametric. If the eccentricity is small, the system will always oscillate about the position of equilibrium with tight string like dumb-bell satellite with changing phase and constant amplitude. 相似文献
18.
F. Mignard 《Earth, Moon, and Planets》1980,23(2):185-201
We present here a model for the tidal evolution of an isolated two-body system. Equations are derived, including the dissipation in the planet as in the satellite, in a frequency dependent lag model. The set of differential equations obtained is still valid for large eccentricity, as well as for all inclinations. The reference plane chosen enables us to study the evolution for both the orbital plane and the equatorial plane.The results obtained show the Moon, after having approached the Earth with small variations for the inclination and the eccentricity, exhibits strong increase for the two parameters in the vicinity of the closest approach. In every case the eccentricity tends towards the value 1, whereas the variations of the in clinations are dependent on the magnitude of the dissipation in the satellite.Some qualitative results are also investigated for the final behaviour of satellites such as Triton and the Galilean satellites. 相似文献
19.
Sergey V. Ershkov 《Earth, Moon, and Planets》2017,120(1):15-30
Tidal interactions between Planet and its satellites are known to be the main phenomena, which are determining the orbital evolution of the satellites. The modern ansatz in the theory of tidal dissipation in Saturn was developed previously by the international team of scientists from various countries in the field of celestial mechanics. Our applying to the theory of tidal dissipation concerns the investigating of the system of ODE-equations (ordinary differential equations) that govern the orbital evolution of the satellites; such an extremely non-linear system of 2 ordinary differential equations describes the mutual internal dynamics for the eccentricity of the orbit along with involving the semi-major axis of the proper satellite into such a monstrous equations. In our derivation, we have presented the elegant analytical solutions to the system above; so, the motivation of our ansatz is to transform the previously presented system of equations to the convenient form, in which the minimum of numerical calculations are required to obtain the final solutions. Preferably, it should be the analytical solutions; we have presented the solution as a set of quasi-periodic cycles via re-inversing of the proper ultra-elliptical integral. It means a quasi-periodic character of the evolution of the eccentricity, of the semi-major axis for the satellite orbit as well as of the quasi-periodic character of the tidal dissipation in the Planet. 相似文献