scholarly journals Interactions between Planets and Small Bodies: Introduction

1998 ◽  
Vol 11 (1) ◽  
pp. 220-222
Author(s):  
M. Marov ◽  
H. Rickman
Keyword(s):  
Solar System ◽  
Scientific Discipline ◽  
Evolutionary Models ◽  
Laboratory Measurements ◽  
Small Bodies ◽  
Great Progress ◽  
History Of ◽  
Impact Phenomena ◽  
Remote Sensing Methods ◽  
Insight Into

The exploration of our Solar System is rapidly growing in importance as a scientific discipline. During the last decades, great progress has been achieved as the result of space missions to planets and small bodies and improved remote-sensing methods, as well as due to refined techniques of laboratory measurements and a rapid progress in theoretical studies, involving the development of various astrophysical and geophysical evolutionary models, based in particular on the approach of comparative planetology. In the crossroads of astronomy and geophysics, recent years have seen a growing understanding of the importance of impact phenomena throughout the history of the Solar System and, therefore, the necessity to get more insight into the problem of interactions of planets and small bodies. This importance is clearly manifested by the observed cratering records of planetary surfaces and such dramatic events as the explosions of the comet P/Shoemaker-Levy 9 fragments in Jupiter’s atmosphere in 1994, that of the Tunguska object over Siberia in 1908, and the Chicxulub event dating back to the end of the Cretaceous.

scholarly journals 3.10 Mariner Mission to Encke 1980

1976 ◽  
Vol 31 ◽  
pp. 346-355 ◽  
Author(s):  
C. M. Yeates ◽  
K. T. Nock ◽  
R. L. Newburn
Keyword(s):  
Solar System ◽  
Early Stage ◽  
Early Period ◽  
Atmospheric Effects ◽  
Formation Processes ◽  
Small Bodies ◽  
Origin And Evolution ◽  
Great Insight ◽  
Insight Into ◽  
Actual Formation

The planetary program has always been conducted with the hope that the results would reveal great insight into the early period of solar system history and perhaps into the actual formation processes themselves. However, little knowledge has been gained of this very early stage for several reasons: The intense surface bombardment of all larger bodies, particularly in the inner solar system during that period; the subsequent differentiation of large bodies; and atmospheric effects and continued bombardment of the surface. The most promising approach to acquisition of knowledge pertaining to the early state of the solar system, its origin and evolution, therefore seems to be in the study of small bodies, e. g., comets and asteroids.

scholarly journals Understanding the trans-Neptunian Solar system; Reconciling the results of serendipitous stellar occultations and the inferences from the cratering record.

2020 ◽  
Author(s):  
Andrew Shannon ◽  
Alain Doressoundiram ◽  
Françoise Roques ◽  
Bruno Sicardy
Keyword(s):  
Solar System ◽  
Semimajor Axis ◽  
Evolutionary Models ◽  
Initial Size ◽  
Small Bodies ◽  
New Horizons ◽  
Mcmc Sampling ◽  
Stellar Occultations ◽  
Formation Conditions ◽  
Optical Surveys

<p>The most pristine remnants of the Solar system's planet formation epoch orbit the Sun beyond Neptune, the small bodies of the trans-Neptunian object populations.  The bulk of the mass is in ~100 km objects, but objects at smaller sizes have undergone minimal collisional processing, with "New Horizons" recently revealing that ~20 km (486958) Arrokoth appears to be a primordial body, not a collisional fragment.  This indicates bodies at these sizes (and perhaps smaller) retain a record of how they were formed.  However, such bodies are impractical to find by optical surveys due to their very low brightnesses.  Their presence can be inferred from the observed cratering record of Pluto and Charon, and directly measured by serendipitous stellar occultations.  These two methods produce conflicting results, with occultations measuring roughly ten times the number of ~km bodies inferred from the cratering record.  We apply MCMC sampling to explore numerical evolutionary models of the outer Solar system to understand what formation conditions can reconcile the occultations and cratering observations.  We find that models where the initial size of bodies decreases with their semimajor axis of formation, and models where the surface density of bodies increases beyond the 2:1 mean-motion resonance with Neptune can produce both sets of observations.  We discuss the astrophysical plausibility of these solutions, and possible future observations tests of them.</p>

scholarly journals Main-Belt Comets as Tracers of Ice in the Inner Solar System

2012 ◽  
Vol 8 (S293) ◽  
pp. 212-218 ◽  
Author(s):  
Henry H. Hsieh
Keyword(s):  
Solar System ◽  
Asteroid Belt ◽  
Main Belt ◽  
Small Bodies ◽  
Water Ice ◽  
History Of ◽  
Compositional History ◽  
Main Asteroid Belt ◽  
Abundance And Distribution ◽  
Ice Sublimation

AbstractAs a recently recognized class of objects exhibiting apparently cometary (sublimation-driven) activity yet orbiting completely within the main asteroid belt, main-belt comets (MBCs) have revealed the existence of present-day ice in small bodies in the inner solar system and offer an opportunity to better understand the thermal and compositional history of our solar system, and by extension, those of other planetary systems as well. Achieving these overall goals, however, will require meeting various intermediate research objectives, including discovering many more MBCs than the currently known seven objects in order to ascertain the population's true abundance and distribution, confirming that water ice sublimation is in fact the driver of activity in these objects, and improving our understanding of the physical, dynamical, and thermal evolutionary processes that have acted on this population over the age of the solar system.

Stellar Evolution

1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild
Keyword(s):  
Solar System ◽  
Stellar Evolution ◽  
Space Craft ◽  
New Techniques ◽  
Substantial Body ◽  
Individual Stars ◽  
The Past ◽  
Evolution Of Galaxies ◽  
History Of ◽  
Fast Flow

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.

Analytical Electron Microscopy of Extraterrestrial Ice Analogs

1990 ◽  
Vol 48 (1) ◽  
pp. 594-595
Author(s):  
D.F. Blake ◽  
LJ. Allamandola ◽  
G. Palmer ◽  
A. Pohorille
Keyword(s):  
Solar System ◽  
Analytical Electron Microscopy ◽  
Biogenic Elements ◽  
Widespread Occurrence ◽  
Interstellar Ice ◽  
Analytical Electron ◽  
History Of ◽  
Interstellar Material ◽  
Astrophysical Ices ◽  
Interstellar Molecular Clouds

The natural history of the biogenic elements H, C, N, O, P and S in the cosmos is of great interest because it is these elements which comprise all life. Material ejected from stars (or pre-existing in the interstellar medium) is thought to condense into diffuse bodies of gravitationally bound gas and dust called cold interstellar molecular clouds. Current theories predict that within these clouds, at temperatures of 10-100° K, gases (primarily H2O, but including CO, CO2, CH3OH, NH3, and others) condense onto submicron silicate grains to form icy grain mantles. This interstellar ice represents the earliest and most primitive association of the biogenic elements. Within these multicomponent icy mantles, pre-biotic organic compounds are formed during exposure to UV radiation. It is thought that icy planetesimals (such as comets) within our solar system contain some pristine interstellar material, including ices, and may have (during the early bombardment of the solar system, ∼4 Ga) carried this material to Earth.Despite the widespread occurrence of astrophysical ices and their importance to pre-biotic organic evolution, few experimental data exist which address the relevant phase equilibria and possible structural states. A knowledge of the petrology of astrophysical ice analogs will allow scientists to more confidently interpret astronomical IR observations. Furthermore, the development and refinement of procedures for analyzing ices and other materials at cryogenic temperatures is critical to the study of materials returned from the proposed Rosetta comet nucleus and Mars sample return missions.

From Dust to Life

2017 ◽  
Author(s):  
John Chambers ◽  
Jacqueline Mitton
Keyword(s):  
Solar System ◽  
Extrasolar Planets ◽  
Planetary Systems ◽  
History Of Astronomy ◽  
Human Origins ◽  
History Of ◽  
The Subject ◽  
Emergence Of Life

The birth and evolution of our solar system is a tantalizing mystery that may one day provide answers to the question of human origins. This book tells the remarkable story of how the celestial objects that make up the solar system arose from common beginnings billions of years ago, and how scientists and philosophers have sought to unravel this mystery down through the centuries, piecing together the clues that enabled them to deduce the solar system's layout, its age, and the most likely way it formed. Drawing on the history of astronomy and the latest findings in astrophysics and the planetary sciences, the book offers the most up-to-date and authoritative treatment of the subject available. It examines how the evolving universe set the stage for the appearance of our Sun, and how the nebulous cloud of gas and dust that accompanied the young Sun eventually became the planets, comets, moons, and asteroids that exist today. It explores how each of the planets acquired its unique characteristics, why some are rocky and others gaseous, and why one planet in particular—our Earth—provided an almost perfect haven for the emergence of life. The book takes readers to the very frontiers of modern research, engaging with the latest controversies and debates. It reveals how ongoing discoveries of far-distant extrasolar planets and planetary systems are transforming our understanding of our own solar system's astonishing history and its possible fate.

The Subaltern Speak- A Study On The Culture Of The Arunachalis With Special Reference To Mamang Dai’s The Legends Of Pensam

2019 ◽  
Vol 5 (4) ◽  
pp. 14-20
Author(s):  
Ms. Cheryl Antonette Dumenil ◽  
Dr. Cheryl Davis
Keyword(s):  
Special Reference ◽  
Small World ◽  
Natural World ◽  
Arunachal Pradesh ◽  
North East India ◽  
North East ◽  
Shared History ◽  
History Of ◽  
And Gender ◽  
Insight Into

North- East India is an under veiled region with an awe-inspiring landscape, different groups of ethnic people, their culture and heritage. Contemporary writers from this region aspire towards a vision outside the tapered ethnic channel, and they represent a shared history. In their writings, the cultural memory is showcased, and the intensity of feeling overflows the labour of technique and craft. Mamang Dai presents a rare glimpse into the ecology, culture, life of the tribal people and history of the land of the dawn-lit mountains, Arunachal Pradesh, through her novel The Legends of Pensam. The word ‘Pensam’ in the title means ‘in-between’,  but it may also be interpreted as ‘the hidden spaces of the heart’. This is a small world where anything can happen. Being adherents of the animistic faith, the tribes here believe in co-existence with the natural world along with the presence of spirits in their forests and rivers. This paper attempts to draw an insight into the culture and gender of the Arunachalis with special reference to The Legends of Pensam by Mamang Dai.

Collected Documents on the History of the Pskov Orthodox Mission: A Recent Publication

2018 ◽  
pp. 306-312
Author(s):  
Veniamin F. Zima ◽  
Keyword(s):  
Personal Data ◽  
Prisoners Of War ◽  
Inner Life ◽  
Great Patriotic War ◽  
Occupied Territories ◽  
History Of ◽  
Underground Resistance ◽  
The Baltic ◽  
The Church ◽  
Insight Into

The reviewed work is devoted to a significant, and yet little-studied in both national and foreign scholarship, issue of the clergy interactions with German occupational authorities on the territory of the USSR in the days of the Great Patriotic War. It introduces into scientific use historically significant complex of documents (1941-1945) from the archive of the Office of the Metropolitan Sergius (Voskresensky) of Vilnius and Lithuania, patriarchal exarch in Latvia and Estonia, and also records from the investigatory records on charges against clergy and employees concerned in the activities of the Pskov Orthodox Mission (1944-1990). Documents included in the publication are stored in the archives of Moscow, St. Petersburg, Estonia, Lithuania, Leningrad, Novgorod, and Pskov regions. They allow some insight into nature, forms, and methods of the Nazi occupational regime policies in the conquered territories (including policies towards the Church). The documents capture religious policies of the Nazis and inner life of the exarchate, describe actual situation of population and clergy, management activities and counterinsurgency on the occupied territories. The documents bring to light connections between the exarchate and German counterintelligence and reveal the nature of political police work with informants. They capture the political mood of population and prisoners of war. There is information on participants of partisan movement and underground resistance, on communication net between the patriarchal exarchate in the Baltic states and the German counterintelligence. Reports and dispatches of the clergy in the pay of the Nazis addressed to the Metropolitan Sergius (Voskresensky) contain detailed activity reports. Investigatory records contain important biographical information and personal data on the collaborators. Most of the documents, being classified, have never been published before.

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