scholarly journals THE ORIGIN AND STABILITY OF BEACHES

2011 ◽  
Vol 1 (6) ◽  
pp. 17 ◽  
Author(s):  
J. W. Hoyle ◽  
G. T. King
Keyword(s):  
Civil Engineer ◽  
Solar System ◽  
Sedimentary Rocks ◽  
Raw Material ◽  
Material Supply ◽  
Sequence Of Events ◽  
The Earth ◽  
Sea Bed ◽  
History Of ◽  
New Material

One should not lose sight of the fact that the origin of beaches goes back into antiquity. The story "begins with the origin of matter and continues through the aeons with the evolution of the solar system and the appearance of the Earth as a fiery ball gyrating in space. As one's focus narrows there is to be seen the cooling of that ball, the formation of dense clouds of water vapour in the atmosphere, the torrential rains and the beginnings of the seas. Perhaps it is at this point that the introduction is completed and the real story of the beaches begins, for with the rains came erosion of the land masses, and the transportation of the eroded material by river and rivulet towards the sea. At the brink of the ocean a brief halt is called in its journey, for here a portion of this eroded material takes position as beaches around die coast, before ultimately joining the remainder in the depths of the sea. For many thousands of years the sediment so formed and transported collected on the sea bed, consolidated and hardened and was transformed into the sedimentary rocks which, by adjustments in the Earth's crust, were later lifted above the surface of the sea to form new islands and continents. Still the rains fall, although perhaps not so heavily as before; still the processes of erosion continue upon the land masses, old and new, still a part of the products of this erosion remain for a while at the coastal fringe before they pass on to the ocean depths - the raw material of what may be, by completion of the cycle, the continents of tomorrow. Such is the sequence of events over a period of millions of years and, as the process continues during the millions of years which the future holds, the existing land masses will no doubt be eroded away and the materials of which they are composed will finally rest again on the bed of the sea. For so long as the seas have washed the shores, and the rains have fallen and reduced the mountains and high places, there have been beaches. Those beaches, which are found today may have existed from time immemorial in some form or other, perhaps since before life appeared on the surface of the Earth. Due to their position in the pattern of Nature they will have changed as the coastline changed, and as the eroded ingredients of the land which formed them changed. They will have grown when the new material supply exceeded the wastage, and they will have diminished when the wastage was more rapid than the replenishment. The changes which are taking place today and which are engaging the attention of the Civil Engineer, form an infinitesimally small incident in the history of the beaches; and in the considerations of the Engineer they should be related to the whole, of which they form a part.

Science and Exploration of the Moon: Overview

2021 ◽  
Author(s):  
Bradley L. Jolliff
Keyword(s):  
Solar System ◽  
Nearest Neighbor ◽  
Space Environment ◽  
Cold Trap ◽  
The Moon ◽  
Early Solar System ◽  
Geologic History ◽  
The Earth ◽  
History Of ◽  
The Impact

Earth’s moon, hereafter referred to as “the Moon,” has been an object of intense study since before the time of the Apollo and Luna missions to the lunar surface and associated sample returns. As a differentiated rocky body and as Earth’s companion in the solar system, much study has been given to aspects such as the Moon’s surface characteristics, composition, interior, geologic history, origin, and what it records about the early history of the Earth-Moon system and the evolution of differentiated rocky bodies in the solar system. Much of the Apollo and post-Apollo knowledge came from surface geologic exploration, remote sensing, and extensive studies of the lunar samples. After a hiatus of nearly two decades following the end of Apollo and Luna missions, a new era of lunar exploration began with a series of orbital missions, including missions designed to prepare the way for longer duration human use and further exploration of the Moon. Participation in these missions has become international. The more recent missions have provided global context and have investigated composition, mineralogy, topography, gravity, tectonics, thermal evolution of the interior, thermal and radiation environments at the surface, exosphere composition and phenomena, and characteristics of the poles with their permanently shaded cold-trap environments. New samples were recognized as a class of achondrite meteorites, shown through geochemical and mineralogical similarities to have originated on the Moon. New sample-based studies with ever-improving analytical techniques and approaches have also led to significant discoveries such as the determination of volatile contents, including intrinsic H contents of lunar minerals and glasses. The Moon preserves a record of the impact history of the solar system, and new developments in timing of events, sample based and model based, are leading to a new reckoning of planetary chronology and the events that occurred in the early solar system. The new data provide the grist to test models of formation of the Moon and its early differentiation, and its thermal and volcanic evolution. Thought to have been born of a giant impact into early Earth, new data are providing key constraints on timing and process. The new data are also being used to test hypotheses and work out details such as for the magma ocean concept, the possible existence of an early magnetic field generated by a core dynamo, the effects of intense asteroidal and cometary bombardment during the first 500 million–600 million years, sequestration of volatile compounds at the poles, volcanism through time, including new information about the youngest volcanism on the Moon, and the formation and degradation processes of impact craters, so well preserved on the Moon. The Moon is a natural laboratory and cornerstone for understanding many processes operating in the space environment of the Earth and Moon, now and in the past, and of the geologic processes that have affected the planets through time. The Moon is a destination for further human exploration and activity, including use of valuable resources in space. It behooves humanity to learn as much about Earth’s nearest neighbor in space as possible.

scholarly journals The early history of the earth

1988 ◽  
Vol 7 (1) ◽  
pp. 38-47
Author(s):  
C. P. Snyman
Keyword(s):  
Solar System ◽  
Laws Of Nature ◽  
Early History ◽  
The Sun ◽  
Natural Phenomena ◽  
The Earth ◽  
History Of ◽  
By Products

In view of the principle of actualism the early history of the earth must be explained on the basis of present-day natural phenomena and the basic Laws of Nature. The study of the solar system leads to the conclusion that the planets were formed as by-products when the sun developed from a rotating cloud of cosmic gas and dust. The protoplanets or planetesimals could have accreted as a result of mutual collisions, during which they could have become partly molten so that they could differentiate into a crust, a mantle and a core on the basis of differences in density.

Stages of Development of Electromechanical Systems of Simulators for Training Cosmonauts to Work in Conditions of Zero Gravity and Low Gravity

2021 ◽  
Vol 64 (2) ◽  
pp. 5-13
Author(s):  
Georgiy Pyatibratov ◽  
◽  
Oleg Kravchenko ◽  
Dmitriy Bogdanov ◽  
Azamat Bekin ◽  
...  
Keyword(s):  
Solar System ◽  
Control Systems ◽  
Space Exploration ◽  
Zero Gravity ◽  
Stages Of Development ◽  
Low Gravity ◽  
The Earth ◽  
History Of ◽  
The Creation ◽  
Technical Solutions

The history of the creation and the stages of development of domestic simulators for training cosmonauts to work in conditions of weightlessness and low gravity of the planets of the solar system are analyzed. The principles of construction of simulators with the use of the force-compensating principle, which provide on the Earth the imitation of the motion of astronauts in zero gravity, are considered. The features of the implementation of simulators of different generations and the stages of development of their electromechanical force-compensating systems are given. The directions for further improvement of control systems and possible technical solutions for the creation of promising simulators for training cosmonauts to solve new problems in the implementation of lunar and Martian space exploration programs are determined.

scholarly journals Lunar exploration: opening a window into the history and evolution of the inner Solar System

2014 ◽  
Vol 372 (2024) ◽  
pp. 20130315 ◽  
Author(s):  
Ian A. Crawford ◽  
Katherine H. Joy
Keyword(s):  
Solar System ◽  
Lunar Exploration ◽  
The Moon ◽  
Moon System ◽  
Origin And Evolution ◽  
The Earth ◽  
Geological Evolution ◽  
History Of ◽  
Rocky Planets

The lunar geological record contains a rich archive of the history of the inner Solar System, including information relevant to understanding the origin and evolution of the Earth–Moon system, the geological evolution of rocky planets, and our local cosmic environment. This paper provides a brief review of lunar exploration to-date and describes how future exploration initiatives will further advance our understanding of the origin and evolution of the Moon, the Earth–Moon system and of the Solar System more generally. It is concluded that further advances will require the placing of new scientific instruments on, and the return of additional samples from, the lunar surface. Some of these scientific objectives can be achieved robotically, for example by in situ geochemical and geophysical measurements and through carefully targeted sample return missions. However, in the longer term, we argue that lunar science would greatly benefit from renewed human operations on the surface of the Moon, such as would be facilitated by implementing the recently proposed Global Exploration Roadmap.

scholarly journals Does the lunar regolith contain secrets of the Solar System? Using the Moon as a cosmic witness plate

2009 ◽  
Vol 5 (S264) ◽  
pp. 475-477 ◽  
Author(s):  
David S. McKay ◽  
Louise Riofrio ◽  
Bonnie L. Cooper
Keyword(s):  
Solar System ◽  
Lunar Regolith ◽  
Lunar Soil ◽  
The Moon ◽  
System A ◽  
The Earth ◽  
Radiation History ◽  
History Of ◽  
Time Capsule ◽  
The Impact

AbstractThe lunar regolith (soil) has recorded a history of the early Moon, the Earth, and the entire solar system. A major goal of the developing lunar exploration program should be to find and play back existing fragments of that tape. By playing back the lunar tape, we can uncover a record of planetary bombardment, as well as solar and stellar variability. The Moon can tell us much about our place in the solar system and in the Universe. The lunar regolith has likely recorded the original meteoritic bombardment of Earth and Moon, a violent cataclysm that may have peaked around 4 GY, and the less intense bombardment occurring since that time. Decrease in bombardment allowed life to develop on Earth. This impact history is preserved as megaregolith layers, ejecta layers, impact melt rocks, and ancient impact breccias. The impact history for the Earth and Moon possibly had profound effects on the origin and development of life. Life may have arrived via meteorite transport from a more quiet body, such as Mars. The solar system may have experienced bursts of severe radiation from the Sun, other stars or from unknown sources. The lunar regolith has also recorded a radiation history in the form of implanted and trapped solar wind and solar flare materials and radiation damage. The Moon can be considered as a giant tape recorder containing the history of the solar system. Lunar soil generated by small impacts will be found sandwiched between layers of basalt or pyroclastic deposits. This filling constitutes a buried time capsule that is likely to contain well-preserved ancient regolith. Study of such samples will show us how the solar system has evolved and changed over time. The lunar recording can provide detailed snapshots of specific portions of solar and stellar variability.

scholarly journals IX. On the tidal friction of a planet attended by several satellites, and on the evolution of the solar system

1881 ◽  
Vol 172 ◽  
pp. 491-535 ◽  
Keyword(s):  
Solar System ◽  
Central Body ◽  
The Sun ◽  
Tidal Friction ◽  
The Earth ◽  
History Of ◽  
The Subject ◽  
Complete Investigation

In previous papers on the subject of tidal friction I have confined my attention principally to the case of a planet attended by a single satellite. But in order to make the investigation applicable to the history of the earth and moon it was necessary to take notice of the perturbation of the sun. In consequence of the largeness of the sun’s mass it was not there requisite to make a complete investigation of the theory of a planet attended by a pair of satellites. In the first part of this paper the theory of the tidal friction of a central body attended by any number of satellites is considered.

Astronomical Influences on Biomagnetic Activity Some 120 MA ago: the Potential for Estimating the Evolution of Ancient Planetary Orbits within the Solar System

1997 ◽  
Vol 161 ◽  
pp. 245-252
Author(s):  
Donald H. Tarling ◽  
Bruno D’argenio ◽  
Marina Iorio
Keyword(s):  
Magnetic Properties ◽  
Biological Activity ◽  
Solar System ◽  
Geomagnetic Field ◽  
Sedimentary Rocks ◽  
The Sun ◽  
The Earth ◽  
Geological Past ◽  
Planetary Orbits ◽  
Rotation Of The Earth

AbstractStudies of the magnetic properties of sedimentary rocks provide a record of biological activity in the geological past of the Earth. There is increasing evidence that the rate of biological activity reflects, in part, the direct and indirect influence of the Earth’s orbit around the Sun. These orbital changes also influence the strength and direction of the geomagnetic field, showing that orbital changes directly affect the processes generating the geomagnetic field. Therefore the presence of these effects means that past changes in the Earth’s orbit and the rate of rotation of the Earth can be investigated from such geological and geophysical records.

Meteorites

2019 ◽  
Author(s):  
Kun Wang ◽  
Randy Korotev
Keyword(s):  
Solar System ◽  
Scientific Evidence ◽  
Human Beings ◽  
Meteorite Impacts ◽  
The Earth ◽  
The World ◽  
Trace Elemental ◽  
History Of ◽  
Meteorite Fall ◽  
Amount Of Knowledge

For thousands of years, people living in Egypt, China, Greece, Rome, and other parts of the world have been fascinated by shooting stars, which are the light and sound phenomena commonly associated with meteorite impacts. The earliest written record of a meteorite fall is logged by Chinese chroniclers in 687 bce. However, centuries before that, Egyptians had been using “heavenly iron” to make their first iron tools, including a dagger found in King Tutankhamun’s tomb that dates back to the 14th century bce. Even though human beings have a long history of observing meteors and utilizing meteorites, we did not start to recognize their true celestial origin until the Age of Enlightenment. In 1794 German physicist and musician Ernst Chladni was the first to summarize the scientific evidence and to demonstrate that these unique objects are indeed from outside of the Earth. After more than two centuries of joint efforts by countless keen amateur, academic, institutional, and commercial collectors, more than 60,000 meteorites have been catalogued and classified in the Meteoritical Bulletin Database. This number is continually growing, and meteorites are found all over the world, especially in dry and sparsely populated regions such as Antarctica and the Sahara Desert. Although there are thousands of individual meteorites, they can be handily classified into three broad groups by simple examinations of the specimens. The most common type is stony meteorite, which is made of mostly silicate rocks. Iron meteorites are the easiest to be preserved for thousands (or even millions) of years on the Earth’s surface environments, and they are composed of iron and nickel metals. The stony-irons contain roughly the same amount of metals and silicates, and these spectacular meteorites are the favorites of many collectors and museums. After 200 years, meteoritics (the science of meteorites) has grown out of its infancy and become a vibrant area of research today. The general directions of meteoritic studies are: (1) mineralogy, identifying new minerals or mineral phases that rarely or seldom found on the Earth; (2) petrology, studying the igneous and aqueous textures that give meteorites unique appearances, and providing information about geologic processes on the bodies upon which the meteorites originates; (3) geochemistry, characterizing their major, trace elemental, and isotopic compositions, and conducting interplanetary comparisons; and (4) chronology, dating the ages of the initial crystallization and later on impacting disturbances. Meteorites are the only extraterrestrial samples other than Apollo lunar rocks and Hayabusa asteroid samples that we can directly analyze in laboratories. Through the studies of meteorites, we have quested a vast amount of knowledge about the origin of the Solar System, the nature of the molecular cloud, the solar nebula, the nascent Sun and its planetary bodies including the Earth and its Moon, Mars, and many asteroids. In fact, the 4.6-billion-year age of the whole Solar System is solely defined by the oldest age dated in meteorites, which marked the beginning of everything we appreciate today.

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