Topographic surfaces and gravitational fields of the Earth, Moon and terrestrial planets

2000 ◽  
Vol 6 (1) ◽  
pp. 56-63
Author(s):  
K.K. Kamensky ◽  
V.S. Kislyuk ◽  
Ya.S. Yatskiv ◽  
◽  
Keyword(s):  
Terrestrial Planets ◽  
Gravitational Fields ◽  
The Earth

scholarly journals Forming terrestrial planets and delivering water

2015 ◽  
Vol 11 (A29B) ◽  
pp. 427-430
Author(s):  
Kevin J. Walsh
Keyword(s):  
Planet Formation ◽  
Semimajor Axis ◽  
Giant Planet ◽  
Terrestrial Planet ◽  
Giant Planets ◽  
Asteroid Belt ◽  
Terrestrial Planets ◽  
The Earth ◽  
Building Models ◽  
Rich Material

AbstractBuilding models capable of successfully matching the Terrestrial Planet's basic orbital and physical properties has proven difficult. Meanwhile, improved estimates of the nature of water-rich material accreted by the Earth, along with the timing of its delivery, have added even more constraints for models to match. While the outer Asteroid Belt seemingly provides a source for water-rich planetesimals, models that delivered enough of them to the still-forming Terrestrial Planets typically failed on other basic constraints - such as the mass of Mars.Recent models of Terrestrial Planet Formation have explored how the gas-driven migration of the Giant Planets can solve long-standing issues with the Earth/Mars size ratio. This model is forced to reproduce the orbital and taxonomic distribution of bodies in the Asteroid Belt from a much wider range of semimajor axis than previously considered. In doing so, it also provides a mechanism to feed planetesimals from between and beyond the Giant Planet formation region to the still-forming Terrestrial Planets.

scholarly journals Life among the Craters

2004 ◽  
Vol 213 ◽  
pp. 199-202
Author(s):  
Harrison H. Schmitt
Keyword(s):  
Terrestrial Planets ◽  
The Moon ◽  
Detailed Understanding ◽  
The Earth ◽  
Planetary Mass ◽  
End Members

The Moon forms one end-member in the planetary mass series Earth-Venus-Mars-Mercury-Asteroids-Moon (Weissman 1999). Having a detailed understanding of the nature and evolution of the two end-members of this series, rather than of just the Earth, has increased the value of other data and inferences by orders of magnitude. As a consequence of obtaining an understanding of the evolution of a second planet, we now can look at other terrestrial planets with far greater insight than ever would have been possible otherwise (Fig. 1).

Late Accretion and the Origin of Water on Terrestrial Planets in the Solar System

2021 ◽  
Author(s):  
Cédric Gillmann ◽  
Gregor Golabek ◽  
Sean Raymond ◽  
Paul Tackley ◽  
Maria Schonbachler ◽  
...  
Keyword(s):  
Solar System ◽  
Long Term Evolution ◽  
Terrestrial Planets ◽  
Evolutionary Pathway ◽  
Giant Impact ◽  
The Earth ◽  
Term Evolution ◽  
Surface Liquid ◽  
Venus Atmosphere

<p>Terrestrial planets in the Solar system generally lack surface liquid water. Earth is at odd with this observation and with the idea of the giant Moon-forming impact that should have vaporized any pre-existing water, leaving behind a dry Earth. Given the evidence available, this means that either water was brought back later or the giant impact could not vaporize all the water.</p><p>We have looked at Venus for answers. Indeed, it is an example of an active planet that may have followed a radically different evolutionary pathway despite the similar mechanisms at work and probably comparable initial conditions. However, due to the lack of present-day plate tectonics, volatile recycling, and any surface liquid oceans, the evolution of Venus has likely been more straightforward than that of the Earth, making it easier to understand and model over its long term evolution.</p><p>Here, we investigate the long-term evolution of Venus using self-consistent numerical models of global thermochemical mantle convection coupled with both an atmospheric evolution model and a late accretion N-body delivery model. We test implications of wet and dry late accretion compositions, using present-day Venus atmosphere measurements. Atmospheric losses are only able to remove a limited amount of water over the history of the planet. We show that late accretion of wet material exceeds this sink. CO<sub>2</sub> and N<sub>2</sub> contributions serve as additional constraints.</p><p>Water-rich asteroids colliding with Venus and releasing their water as vapor cannot explain the composition of Venus atmosphere as we measure it today. It means that the asteroidal material that came to Venus, and thus to Earth, after the giant impact must have been dry (enstatite chondrites), therefore preventing the replenishment of the Earth in water. Because water can obviously be found on our planet today, it means that the water we are now enjoying on Earth has been there since its formation, likely buried deep in the Earth so it could survive the giant impact. This in turn suggests that suggests that planets likely formed with their near-full budget in water, and slowly lost it with time.</p>

scholarly journals Vortex-Induced Vibration: the slower deceleration of the west bank leads to the shortening of the Humen Bridge in Guangdong, China

2020 ◽  
Author(s):  
Haili Ran ◽  
Xiaoyong Lu ◽  
Ruohan Zheng ◽  
Cui Yang ◽  
Qiuyun Liu
Keyword(s):  
Potential Energy ◽  
Civil Engineering ◽  
West Bank ◽  
Large Mass ◽  
Small Mass ◽  
The West ◽  
Vortex Induced Vibration ◽  
Gravitational Fields ◽  
The Earth ◽  
Engineering Projects

The Earth self-rotates in the solar and lunar gravitational fields. According to Newton’s Law of Inertia, large mass accelerates and decelerates more slowly than smaller masses, whereas small mass accelerates and decelerates more quickly than larger mass, which gives rise to stress when potential energy is present, damaging civil engineering projects. Humen Bridge of Guangdong, China and two century-old dams in Michigan which were affected recently can be explained by this theory.

scholarly journals Chemistry of atmospheres formed during accretion of the Earth and other terrestrial planets

Icarus ◽  
2010 ◽  
Vol 208 (1) ◽  
pp. 438-448 ◽  
Author(s):  
Laura Schaefer ◽  
Bruce Fegley
Keyword(s):  
Terrestrial Planets ◽  
The Earth

scholarly journals Jupiter’s decisive role in the inner Solar System’s early evolution

2015 ◽  
Vol 112 (14) ◽  
pp. 4214-4217 ◽  
Author(s):  
Konstantin Batygin ◽  
Greg Laughlin
Keyword(s):  
Solar System ◽  
Dynamical Evolution ◽  
Decisive Role ◽  
Terrestrial Planets ◽  
The Sun ◽  
Mean Motion Resonances ◽  
The Earth ◽  
Short Period ◽  
Orbital Periods ◽  
Gas Drag

The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ≈ 1.5 AU before reversing direction, can explain the low overall mass of the Solar System’s terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter’s inward migration entrained s ≳ 10−100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System’s terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution.

scholarly journals Design and ballistic analysis of the mission for long-term study of the asteroid Apophis by a nanosatellite with an electric rocket propulsion system

2020 ◽  
Vol 4 (3) ◽  
pp. 161-170
Author(s):  
O. L. Starinova ◽  
E. A. Sergaeva ◽  
A. Yu. Shornikov
Keyword(s):  
Propulsion System ◽  
Gravitational Attraction ◽  
Term Study ◽  
Small Bodies ◽  
Rocket Propulsion ◽  
Gravitational Fields ◽  
Optimal Speed ◽  
Long Term Study ◽  
The Earth

The paper considers non-spherical objects with low gravitational attraction, such as asteroids, satellites of the planet and comets. We considered possibility of a mission to small bodies of the solar system of irregular shape on the example of the asteroid Apophis. The authors of the article suggest using a nanoclass spacecraft with an electric rocket propulsion system for a long mission to study Apophis. The purpose of this work is to determine the necessary costs of the working body for all stages of the mission, which includes reaching the asteroid, forming and maintaining a given orbit relative to it. The gravity of the Earth, Sun, and asteroid is taken into account when modeling the controlled movement of the spacecraft. When a spacecraft is moving relative to an asteroid, its gravitational field is described as a superposition of the gravitational fields of two rotating massive points. In this paper, it is proposed to divide the mission into two sections for preliminary ballistic design. The first optimal speed heliocentric flight Earth-asteroid Apophis with the alignment of the speed of the spacecraft and the asteroid. The second is the movement in the vicinity of the asteroid, which includes the optimal speed maneuver for forming the working orbit and maintaining the working orbit for a given time.

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