scholarly journals Ice On Planets of the Solar System

1984 ◽  
Vol 30 (106) ◽  
pp. 259-274
Author(s):  
M.S. Krass
Keyword(s):  
Solar System ◽  
Strain State ◽  
Considerable Proportion ◽  
Temperature Variations ◽  
The Earth ◽  
Galilean Moons ◽  
Short Period ◽  
Main Components ◽  
Galilean Moons Of Jupiter

AbstractSeveral aspects of space glaciology are considered in the paper. Estimates of the water content of the Earth, Mars, and the Galilean moons of Jupiter are corrected. A considerable proportion of the total amount of water in the solar system is localized near Jupiter; part of this water is contained as ice in glaciations, glacial caps, and ice crust on the planets. Ice is one of the main components of the surface of some planets. The major amount of ice on Mars is contained in a permafrost layer of mean thickness about 3 km. The model of an ice crust floating on a water mantle is considered for Jupiter’s moon Europa. It is shown that for definite values of certain parameters this crust may be subject to destruction due to the instability of its proper oscillations, which explains the numerous systems of fractures and cracks observed on Europa’s surface. The stress-strain state of such an ice crust is calculated within the framework of a non-linear thermo-elasticity model. The role of short-period temperature variations at Europa’s surface is estimated and the peculiarities of relief observed on this planet are analysed.

scholarly journals Ice On Planets of the Solar System

1984 ◽  
Vol 30 (106) ◽  
pp. 259-274 ◽  
Author(s):  
M.S. Krass
Keyword(s):  
Solar System ◽  
Strain State ◽  
Considerable Proportion ◽  
Temperature Variations ◽  
The Earth ◽  
Galilean Moons ◽  
Short Period ◽  
Main Components ◽  
Galilean Moons Of Jupiter

AbstractSeveral aspects of space glaciology are considered in the paper. Estimates of the water content of the Earth, Mars, and the Galilean moons of Jupiter are corrected. A considerable proportion of the total amount of water in the solar system is localized near Jupiter; part of this water is contained as ice in glaciations, glacial caps, and ice crust on the planets. Ice is one of the main components of the surface of some planets. The major amount of ice on Mars is contained in a permafrost layer of mean thickness about 3 km. The model of an ice crust floating on a water mantle is considered for Jupiter’s moon Europa. It is shown that for definite values of certain parameters this crust may be subject to destruction due to the instability of its proper oscillations, which explains the numerous systems of fractures and cracks observed on Europa’s surface. The stress-strain state of such an ice crust is calculated within the framework of a non-linear thermo-elasticity model. The role of short-period temperature variations at Europa’s surface is estimated and the peculiarities of relief observed on this planet are analysed.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

scholarly journals On the Role of the Earth-Moon System in the Stability of the Inner Solar System

1999 ◽  
Vol 117 (5) ◽  
pp. 2561-2562 ◽  
Author(s):  
F. Namouni ◽  
C. D. Murray
Keyword(s):  
Solar System ◽  
Moon System ◽  
The Earth ◽  
The Stability

scholarly journals Slow and Fast Diffusion in Asteroid-Belt Resonances: A Review

1999 ◽  
Vol 172 ◽  
pp. 25-37
Author(s):  
S. Ferraz-Mello
Keyword(s):  
Solar System ◽  
Chaotic Behaviour ◽  
Asteroid Belt ◽  
Fast Diffusion ◽  
Outer Solar System ◽  
Recent Advances ◽  
Short Period ◽  
Hecuba Gap

AbstractThis paper reviews recent advances in several topics of resonant asteroidal dynamics as the role of resonances in the transportation of asteroids and asteroidal debris to the inner and outer solar system; the explanation of the contrast of a depleted 2/1 resonance (Hecuba gap) and a high-populated 3/2 resonance (Hilda group); the overall stochasticity created in the asteroid belt by the short-period perturbations of Jupiter’s orbit, with emphasis in the formation of significant three-period resonances, the chaotic behaviour of the outer asteroid belt, and the depletion of the Hecuba gap.

scholarly journals Jupiter – friend or foe? II: the Centaurs

2008 ◽  
Vol 8 (2) ◽  
pp. 75-80 ◽  
Author(s):  
J. Horner ◽  
B.W. Jones
Keyword(s):  
Solar System ◽  
Kuiper Belt ◽  
Giant Planet ◽  
Mass Extinctions ◽  
The Earth ◽  
Impact Rate ◽  
Short Period ◽  
Impact Risk ◽  
Life On Earth ◽  
The Impact

AbstractIt has long been assumed that the planet Jupiter acts as a giant shield, significantly lowering the impact rate of minor bodies upon the Earth, and thus enabling the development and evolution of life in a collisional environment which is not overly hostile. In other words, it is thought that, thanks to Jupiter, mass extinctions have been sufficiently infrequent that the biosphere has been able to diversify and prosper. However, in the past, little work has been carried out to examine the validity of this idea. In the second of a series of papers, we examine the degree to which the impact risk resulting from objects on Centaur-like orbits is affected by the presence of a giant planet, in an attempt to fully understand the impact regime under which life on Earth has developed. The Centaurs are a population of ice-rich bodies which move on dynamically unstable orbits in the outer Solar system. The largest Centaurs known are several hundred kilometres in diameter, and it is certain that a great number of kilometre or sub-kilometre sized Centaurs still await discovery. These objects move on orbits which bring them closer to the Sun than Neptune, although they remain beyond the orbit of Jupiter at all times, and have their origins in the vast reservoir of debris known as the Edgeworth–Kuiper belt that extends beyond Neptune. Over time, the giant planets perturb the Centaurs, sending a significant fraction into the inner Solar System where they become visible as short-period comets. In this work, we obtain results which show that the presence of a giant planet can act to significantly change the impact rate of short-period comets on the Earth, and that such planets often actually increase the impact flux greatly over that which would be expected were a giant planet not present.

scholarly journals D/H ratios of the inner Solar System

2017 ◽  
Vol 375 (2094) ◽  
pp. 20150390 ◽  
Author(s):  
L. J. Hallis
Keyword(s):  
Solar System ◽  
Giant Planet ◽  
Published Data ◽  
Solar System Formation ◽  
Atmospheric Processes ◽  
The Past ◽  
The Earth ◽  
Planetary Bodies ◽  
Original Water

The original hydrogen isotope (D/H) ratios of different planetary bodies may indicate where each body formed in the Solar System. However, geological and atmospheric processes can alter these ratios through time. Over the past few decades, D/H ratios in meteorites from Vesta and Mars, as well as from S- and C-type asteroids, have been measured. The aim of this article is to bring together all previously published data from these bodies, as well as the Earth, in order to determine the original D/H ratio for each of these inner Solar System planetary bodies. Once all secondary processes have been stripped away, the inner Solar System appears to be relatively homogeneous in terms of water D/H, with the original water D/H ratios of Vesta, Mars, the Earth, and S- and C-type asteroids all falling between δD values of −100‰ and −590‰. This homogeneity is in accord with the ‘Grand tack’ model of Solar System formation, where giant planet migration causes the S- and C-type asteroids to be mixed within 1 AU to eventually form the terrestrial planets. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’.

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 Jupiter – friend or foe? IV: the influence of orbital eccentricity and inclination

2012 ◽  
Vol 11 (3) ◽  
pp. 147-156 ◽  
Author(s):  
J. Horner ◽  
B. W. Jones
Keyword(s):  
Solar System ◽  
Asteroid Belt ◽  
Slight Reduction ◽  
Orbital Eccentricity ◽  
Orbital Inclination ◽  
The Earth ◽  
Impact Rate ◽  
Impact Flux ◽  
Short Period ◽  
The Impact

AbstractFor many years, it has been assumed that Jupiter has prevented the Earth from being subject to a punishing impact regime that would have greatly hindered the development of life. Here, we present the fourth in a series of dynamical studies investigating this hypothesis. In our earlier work, we examined the effect of Jupiter's mass on the impact rate experienced by the Earth. Here, we extend that approach to consider the influence of Jupiter's orbital eccentricity and inclination on the impact rate from asteroidal bodies and short-period comets. We first considered scenarios in which Jupiter's orbital eccentricity was somewhat higher and somewhat lower than that in our Solar System, for a variety of ‘Jupiter’ masses. We find that Jupiter's orbital eccentricity plays a moderate role in determining the impact flux at Earth, with more eccentric orbits resulting in a noticeably higher impact rate of asteroids than is the case for more circular orbits. This is particularly pronounced at high ‘Jupiter’ masses. For the short-period comets, the same effect is clearly apparent, albeit to a much lesser degree. The flux of short-period comets impacting the Earth is slightly higher for more eccentric Jovian orbits. We also considered scenarios in which Jupiter's orbital inclination was greater than that in our Solar System. Increasing Jupiter's orbital inclination greatly increased the flux of asteroidal impactors upon the Earth. However, at the highest tested inclination, the disruption to the Asteroid belt was so great that the belt would be entirely depleted after an astronomically short period of time. In such a system, the impact flux from asteroid bodies would therefore be very low, after an initial period of intense bombardment. By contrast, the influence of Jovian inclination on impacts from short-period comets was very small. A slight reduction in the impact flux was noted for the moderate and high inclination scenarios considered in this work – the results for inclinations of 5° and 25° were essentially identical.

Welcome to the Neighbourhood: Belonging to the Universe

Leonardo ◽  
2005 ◽  
Vol 38 (5) ◽  
pp. 383-388
Author(s):  
Adam Nieman
Keyword(s):  
Solar System ◽  
Public Engagement ◽  
Space Travel ◽  
The Earth ◽  
Public Engagement With Science ◽  
Space Art ◽  
The Universe

Space travel could be an experience available to everyone. This paper describes Welcome to the Neighbourhood, a combination of sculpture and multimedia designed to help people inhabit the solar system (without leaving the earth). The project aims to empower astronomers and nonastronomers alike to form an authentic conception of their place in the cosmos. The author discusses the sculptures that inspired the idea for the project, including the largest known kinetic sculpture ever built (60 light-years across), and then outlines Welcome to the Neigh-bourhood in the context of a broader discussion of public engagement with science and the role of space art in transforming people's experience of “being in the universe.”

Lunar chronology as determined from the radiometric ages of returned lunar sample

1977 ◽  
Vol 285 (1327) ◽  
pp. 137-143 ◽  
Keyword(s):  
Solar System ◽  
Lead Isotopes ◽  
Short Interval ◽  
Rapid Decline ◽  
The Moon ◽  
The Earth ◽  
Short Period ◽  
Radiometric Ages ◽  
Flow Activity ◽  
Lunar Chronology

We have heard earlier in this Discussion Meeting that from the systematics of Sr and Pb isotopes in lunar samples, it is possible to ascertain that the Moon had a solid crust about 4.6 Ga ago, that is, very soon after the formation of the solar system. In addition, it would seem that the major ring-basins on the Earth side of the Moon were all formed before 3.8 Ga ago. After the formation of the basins by impact, there was extensive magmatic activity in the form of basalt flows, expecially in the major ring-basins. About 3.1 Ga ago, all major lava-flow activity on the Moon had ceased. This outline of lunar chronology is accepted in practically all proposed interpretations of the radiometric ages. The first 600 Ma of lunar chronology is not as clear. During this time the multi-ring basins were formed. It has been proposed by G. Turner and by G. J. Wasserburg at this meeting, that the multi-ring basins formed in a rather short interval of time, perhaps as short as 100 Ma. This would imply an intense cratering rate some 3.9 Ga ago and a rapid decline in cratering rate thereafter. Such an event would have probably greatly altered the other bodies in the solar system, especially the Earth, and as such is of no small significance. It has been pointed out previously by Tera et al. (1974) that an alternative interpretation of the radiometric data is that widespread, simultaneous metamorphism (which the systematics of the lead isotopes in the highland rocks seems to imply) could as well result from a single widespread event such as Imbrium as from a multiple basin-forming sequence in a short period of time. In that case, the chronology of the multi-ring basins is an open question.

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