Academic literature on the topic 'Moon: Considered as a Planet, a World, and a Satellite'

ABSTRACT Exoplanet discoveries have motivated numerous efforts to find unseen populations of exomoons, yet they have been unsuccessful. A plausible explanation is that most discovered planets are located on close-in orbits, which would make their moons prone to tidal evolution and orbital detachment. In recent models of tidally driven migration of exomoons, evolving planets might prevent what was considered their most plausible fate (i.e. colliding against their host planet), favouring scenarios where moons are pushed away and reach what we define as the satellite tidal orbital parking distance ($a_{\rm \mathrm{stop}}$), which is often within the critical limit for unstable orbits and depends mainly on the system’s initial conditions: mass ratio, semimajor axes, and rotational rates. Using semi-analytical calculations and numerical simulations, we calculate $a_{\rm \mathrm{stop}}$ for different initial system parameters and constrain the transit detectability of exomoons around close-in planets. We found that systems with Mm/Mp ≥ 10−4, which are less likely to form, are also stable and detectable with present facilities (e.g. Kepler and TESS) through their direct and secondary effects in planet + moon transit, as they are massive, oversized, and migrate slowly. In contrast, systems with lower moon-to-planet mass ratios are ephemeral and hardly detectable. Moreover, any detection, confirmation, and full characterization would require both the short cadence capabilities of TESS and high photometric sensitivity of ground-based observatories. Finally, despite the shortage of discovered long-period planets in currently available data bases, the tidal migration model adopted in this work supports the idea that they are more likely to host the first detectable exomoon.

AbstractThe hypothesis of the explosion of a number of planets and moons of our Solar System during its 4.6-billion-year history is in excellent accord with all known observational constraints, even without adjustable parameters or ad hoc helper hypotheses. Many of its boldest predictions have been fulfilled. In most instances, these predictions were judged highly unlikely by the current standard models. Moreover, in several cases, the entire exploded planet model was at risk of being falsified if the predictions failed. The successful predictions include: (1) satellites of asteroids; (2) satellites of comets; (3) salt water in meteorites; (4) ‘roll marks’ leading to boulders on asteroids; (5) the time and peak rate of the 1999 Leonid meteor storm; (6) explosion signatures for asteroids; (7) the strongly spiked energy parameter for new comets; (8) the distribution of black material on slowly rotating airless bodies; (9) splitting velocities of comets; (10) the asteroid-like nature of Deep Impact target Comet Tempel 1; and (11) the presence of high-formation-temperature minerals in the Stardust comet dust sample return. In physics and astronomy, hypotheses are either falsified if their predictions fail, or proved to be of value if they succeed. By all existing evidence, the exploded planet hypothesis has proved far more useful than the half-dozen or so hypotheses it would replace. Among the many important corollaries are these. (a) Perhaps as many as six former planets of our Solar System have exploded over its 4.6-billion-year history. (b) In particular, Mars is not an original planet, but a former moon of an exploded planet. (c) As a major player in Solar System evolution, the exploded planet scenario must be considered as a likely propagation vehicle for the spread of biogenic organisms. We conclude with a brief mention of three possible planetary explosion mechanisms.

As civilization evolves through time, humans had begun to unfold the capabilities of the mind to create things and it had evolved through the great span of time from ancient world to the modern era but human civilization cannot be considered advance yet until it is able to reach the nearest planet from earth. As human had begun to embrace the modern world of digital technology and space travel, it had become a burden for mankind as to how would it be able to reach the moon and the nearest planet from earth. The primary concern for space travel is fuel. The fuel that would be capable of transporting a ship from this planet earth to the next nearest planet in the solar system, the answer to this question might be here on earth as well, the very element that came from space and form our beautiful and amazing planet, it is water. Water is a very vital element to human existence although many take it for granted but water is truly our life and time will come that water will be a very valued commodity in this planet.

As civilization evolves through time, humans had begun to unfold the capabilities of the mind to create things and it had evolved through the great span of time from ancient world to the modern era but human civilization cannot be considered advance yet until it is able to reach the nearest planet from earth. As human had begun to embrace the modern world of digital technology and space travel, it had become a burden for mankind as to how would it be able to reach the moon and the nearest planet from earth. The primary concern for space travel is fuel. The fuel that would be capable of transporting a ship from this planet earth to the next nearest planet in the solar system, the answer to this question might be here on earth as well, the very element that came from space and form our beautiful and amazing planet, it is water. Water is a very vital element to human existence although many take it for granted but water is truly our life and time will come that water will be a very valued commodity in this planet.

Desertification is a land degradation in arid, semi-arid and dry sub-humid areas as a result of various factors, including climate change and human activities. The Aral Sea is called the once large, and now almost dry, salt lake, which today looks like a large salt desert. Its drying is considered one of the greatest environmental disasters of our time, because only 50 years ago it was one of the four largest lakes on our planet. In the 1990s, the western world learned about the environmental disaster of what used to be the fourth largest lake in the world - The Aral Sea. The abrupt drying of the Aral Sea led to the intensive development of desertification processes in the region and the formation of the new man-made Aralkum desert. The main method for determining the soil degradation of the Aralkum desert is the calculation of indices. The selected methods are widely known and repeatedly applied in world practice methods for processing satellite images. So, all of the listed spectral indices are universal. The uniqueness of this technique lies in the determination of the exact ranges of values for each of the spectral indices in the identification of various indicators of desertification.

In recent years, the astronomy teaching community has been called upon to include more cultural aspects of the influence of astronomy across the world in university courses. As an important component connecting the science of predictable sky alignments with historical human events, students studying the history of science and astronomy often find it cognitively challenging to recognize the fact that till the 16th century AD the most fundamental picture of the planetary system had been distorted with the sun considered to be the fourth planet of the earth rather than the center of our modern planetary system. Similarly, students are often amazed in realizing that the vast majority of all professional and knowledgeable astronomers had also believed that planets control the destiny of all human beings,and, in particular, in predicting extreme events. In this presentation, we concentrate on such impacts of astronomers who stood behind the determination of the chronology of the Bible. Having illustrated that the ancient astronomers believed that when the Sun, the Moon, and the first point of Aries form a straight celestial line, important historical events described in the Bible could be revealed, and one could systematically examine the relative positions of these three celestial objects when events would occur and symbolize for the sages the end of an era. We first describe how the largest celestial separation between the sun, the moon, and the Vernal Equinox (VE) was identified by the writers of the chronology to occur in association with the destruction of Solomon’s Temple; and then we illustrate the additional result that such a separation was also made to be associated with a biblical flood.

Sedimentary rocks provide records of past surface and subsurface processes and environments. The first step in the study of the sedimentary rock record of another world is to learn to recognize their occurrences in images from instruments aboard orbiting, flyby, or aerial platforms. For two decades, Mars has been known to have sedimentary rocks; however, planet-wide identification is incomplete. Global coverage at 0.25–6 m/pixel, and observations from the Curiosity rover in Gale crater, expand the ability to recognize Martian sedimentary rocks. No longer limited to cases that are light-toned, lightly cratered, and stratified—or mimic original depositional setting (e.g., lithified deltas)—Martian sedimentary rocks include dark-toned examples, as well as rocks that are erosion-resistant enough to retain small craters as well as do lava flows. Breakdown of conglomerates, breccias, and even some mudstones, can produce a pebbly regolith that imparts a “smooth” appearance in satellite and aerial images. Context is important; sedimentary rocks remain challenging to distinguish from primary igneous rocks in some cases. Detection of ultramafic, mafic, or andesitic compositions do not dictate that a rock is igneous, and clast genesis should be considered separately from the depositional record. Mars likely has much more sedimentary rock than previously recognized.

Earth observation data can help us understand and address some of the grand challenges and threats facing us today as a species and as a planet, for example climate change and its impacts and sustainable use of the Earth’s resources. However, in order to have confidence in earth observation data, measurements made at the surface of the Earth, with the intention of providing verification or validation of satellite-mounted sensor measurements, should be trustworthy and at least of the same high quality as those taken with the satellite sensors themselves. Metrology tells us that in order to be trustworthy, measurements should include an unbroken chain of SI-traceable calibrations and comparisons and full uncertainty budgets for each of the in situ sensors. Until now, this has not been the case for most satellite validation measurements. Therefore, within this context, the European Space Agency (ESA) funded a series of Fiducial Reference Measurements (FRM) projects targeting the validation of satellite data products of the atmosphere, land, and ocean, and setting the framework, standards, and protocols for future satellite validation efforts. The FRM4SOC project was structured to provide this support for evaluating and improving the state of the art in ocean colour radiometry (OCR) and satellite ocean colour validation through a series of comparisons under the auspices of the Committee on Earth Observation Satellites (CEOS). This followed the recommendations from the International Ocean Colour Coordinating Group’s white paper and supports the CEOS ocean colour virtual constellation. The main objective was to establish and maintain SI traceable ground-based FRM for satellite ocean colour and thus make a fundamental contribution to the European system for monitoring the Earth (Copernicus). This paper outlines the FRM4SOC project structure, objectives and methodology and highlights the main results and achievements of the project: (1) An international SI-traceable comparison of irradiance and radiance sources used for OCR calibration that set measurement, calibration and uncertainty estimation protocols and indicated good agreement between the participating calibration laboratories from around the world; (2) An international SI-traceable laboratory and outdoor comparison of radiometers used for satellite ocean colour validation that set OCR calibration and comparison protocols; (3) A major review and update to the protocols for taking irradiance and radiance field measurements for satellite ocean colour validation, with particular focus on aspects of data acquisition and processing that must be considered in the estimation of measurement uncertainty and guidelines for good practice; (4) A technical comparison of the main radiometers used globally for satellite ocean colour validation bringing radiometer manufacturers together around the same table for the first time to discuss instrument characterisation and its documentation, as needed for measurement uncertainty estimation; (5) Two major international side-by-side field intercomparisons of multiple ocean colour radiometers, one on the Atlantic Meridional Transect (AMT) oceanographic cruise, and the other on the Acqua Alta oceanographic tower in the Gulf of Venice; (6) Impact and promotion of FRM within the ocean colour community, including a scientific road map for the FRM-based future of satellite ocean colour validation and vicarious calibration (based on the findings of the FRM4SOC project, the consensus from two major international FRM4SOC workshops and previous literature, including the IOCCG white paper on in situ ocean colour radiometry).

The aim of this work is to identify the global trends in the use of low-orbit spacecraft constellations, which have a number of substantial advantages in Earth remote sensing (ERS). Much attention is given to the construction of large constellations of single- and different-type spacecraft by foreign companies and operators, such as Digital Globe, Planet Labs, Black Sky, Satellogic S.A. etc., and to the plans of deployment of constellations of this type in the USA, China, Japan, Canada, Europe, and other countries. The characteristics of the various, mainly commercial, low-orbit constellations of optoelectronic Earth observation spacecraft put into orbit over the past five years are considered. It is shown that low-orbit spacecraft constellations can be used to good advantage in the solution of numerous socio-economic problems, such as geodesy and cartography, urban development, transport infrastructure, crop estimate, environmental monitoring, health monitoring, etc., and new problems aimed at prompt continuous monitoring of various objects. The paper presents a comparative analysis of the technical implementations and ways of achievement of the main target spacecraft characteristics, such as information performance, capture range, revisit time, geodetic connection accuracy, imaging immediacy, and the possibility of stereo and video imaging by satellite constellations. It is shown that the construction of large low-orbit constellations is a new trend in the world astronautics, which requires systematic methods for their design and control. The results obtained allows one to make recommendations on the design of low-orbit constellations of home ERS spacecraft, in particular on the development of orbit determination models and algorithms and spacecraft dynamics models.

Tamil science is the knowledge that has traditionally been developed, used and explained scientifically by Tamils. It also refers to the contribution that Tamil is making to science today. Tamil science is found in many fields such as linguistics, medicine, architecture, agriculture, biology, mathematics and astronomy. It is noteworthy that the Tamils ​​who had various technologies also had the basic science for it. Sangam literature is interspersed with versatile messages. Admired as world literature, it contains news from a variety of disciplines. It is known that the Sangam periodicals became versatile due to this. Many world scholars have studied and praised the astronomical news found by the Tamils. Tamils ​​refer to those who know astronomy as 'virgins'. Literary evidence also suggests that the computer predicts time with the motions of a planet orbiting in the sky. The literature is a testament to the fact that Tamils ​​are the ones who know the scientific method of measuring the planets and atmospheres of the sky, their movements and time scales. The Sangam poets knew that there were various planets and galaxies in the sky. News about the Sun, Earth, Jupiter, Mercury, Venus, Saturn, and the satellite Moon is found in the association songs. News about dental galaxies has also been reported in Sangam literature. It is also possible to know that the Tamils ​​who guided the polar fish at night knew the four directions during the day with the help of the sun.

This chapter considers how the very existence of the Moon, the only large satellite in the inner solar system, is a puzzle. The Moon is sufficiently large that one would think of it as a planet if it traveled around the Sun rather than Earth. Much of what the public now knows about the Moon comes from space missions, beginning in the 1960s and early 1970s. Six American Apollo missions each landed two astronauts on the surface. Three of the Soviet Union's unmanned Luna spacecraft touched down on the surface and then returned to Earth. After a long gap, lunar exploration resumed in the 1990s, when NASA's Clementine and Lunar Prospector spacecraft went into orbit. Recently, the pace of exploration has increased again, with the European Space Agency, Japan, China, and India, as well as NASA, all sending missions to the Moon.

Abstract This chapter looks into the theories on the formation of the Solar System. It includes short summaries of ancient myths about how the world was formed. This chapter regards collisions as responsible for the growth of terrestrial planets and the Solar System. Collisions are also a means of bringing together different components and creating new possibilities. In addition, it also cites the possibility of collisions forming another Earth-like planet. NASA’s Kepler satellite, commissioned in order to measure planet dimensions and to look for more exoplanets, is considered as a game changer. It is hoped that as technologies like the telescope continue to become more powerful, more exploration of life on other planets can be conducted and studies of celestial bodies will become more accurate.

On 24 December 1968, as they watched the half-illuminated earthrise over the surface of the moon, the crew of the Apollo 8 lunar mission captured an image that changed humankind’s view of our planet and our place on it. The earthrise image and other iconic global images like the “blue marble” photo taken by the crew of Apollo 17 in 1972 gave us, for the first time, a global view of our fragile home within the vastness of space. These early global images helped promote environmental awareness around the world and were instrumental in the development of the field of remote sensing (Lowman 1999). However, it would take some time for the research community to compile and use global-scale imagery from space in the ecological sciences. Improvements in passive and active remote sensing systems placed in orbit by national governments and the growing commercial satellite sector have given us an “end-to-end” remote sensing capability that allows us to make measurements of important environmental phenomena from very local to global spatial scales (of course, airborne remote sensing systems have long enhanced our ability to capture information at local scales). Data depicting the social and economic drivers of biodiversity loss are also available globally from a variety of sources. These different data sets can now be brought together with powerful, affordable, spatially referenced computing technologies, e.g., GIS and GPS, which were unimaginable when the Apollo missions sent back their images. The entire Apollo spacecraft’s computing power was less than that of today’s mobile phone. Taken together, these advances have made it possible to grapple with the complexities and scale of addressing conservation challenges at the global level. This chapter elaborates the role of remote sensing as one among several catalysts driving the development of new approaches to ecology and conservation biology at the global level. In the early 1980s, NASA initiated its Global Habitability program (NASA 1983; Waldrop 1986; Running et al. 2004). This program sought to answer the big question of how the biosphere partitions its energy and mass.

Hablar de periferia hoy implica deber revisar el significado mismo de la palabra. La de frontera parece la definición más apta para describir la periferia contemporánea, pudiéndose aplicar a todos los asentamientos a baja densidad que, en las últimas décadas, inexorablemente rodearon las grandes ciudades - y, no solamente las grandes - yendo a ocupar territorios casi siempre ex agrícolas. Una periferia que se caracteriza básicamente por ser “incompleta”, obvio efecto del incumplimiento de los procesos, tanto espontáneos como planificados, que la produjeron. La escena romana es un extenso colector de periferias, diferentes y no homogéneas, por lo general deterioradas, nacidas a partir del final de la Segunda Guerra Mundial y el crecimiento de las cuales llegó hasta hoy siguiendo parcialmente el dibujo de un plan urbanístico. Sin embargo la periferia espontánea posee casi siempre rasgos afirmados de una “calidad” que en ésas planificadas es escasa o totalmente ausente. Son periferias heterogéneas sobre todo de carácter ilegal que unen la ausencia substancial de espacios públicos de relación, de “lugares centrales”, a una provisionalidad que acentúe el carácter de periferia de las mismas. Las primeras periferias nacen de la “necesidad” - vivir, trabajar, descansar - en un momento en el cual la administración pública no puede o no quiere hacer frente a la cuestión de la vivienda; en el curso de los años este modelo de asentamiento se consolida y comienza a auto reproducirse, cambiando peligrosamente sus características hasta perder su carácter de “necesidad”. La casa individual con jardín, lejos del centro de la ciudad, se transformó en uno de los desiderata más difusos de los últimos años, de donde las ciudades comenzaron a ser contaminadas verdaderamente en gran parte - en círculo vicioso - por el trafico generado de aquellos que viven en las periferias lecha y deben llegar cotidianamente al centro de la ciudad con medios privados. La gente se ha “acostumbrado” a vivir en estas periferias heterogéneas y el problema de la “ausencia de ciudad” no viene mas percibido como un problema primario pero las exigencias se limitan a más servicios y mejor movilidad, pública y privada. Entonces, en treinta años se transformó el concepto de vivienda, el de ciudad y el de periferia. Pero a este fenómeno se acompaña una decadencia sensible de la calidad de la vida y, por lo tanto, del ambiente. Hay un vínculo muy estrecho entre nacimiento y difusión de las periferias e inicio del proceso, aun en acto, de difusión y dispersión urbana. El punto de ruptura de la tradición del asentamiento, esa cultura de orígenes antiguas y casi universales que se transmitió probablemente oralmente de padre en hijo y que era, por todos, conocida, se pone a fines de los años sesenta e inicio de los setenta. Una transformación que lleva a un asentamiento difuso de carácter residencial, con densidad muy baja (menos de 15 hab/ha. y menos de 1 m3/m2), unido a los centros principales por medio de algunas rutas o, en los casos más afortunados, de infraestructuras ferroviarias con las cuales fueron garantizadas las conexiones con los lugares del estudio y del trabajo y del tiempo libre. Se transformaron las modalidades de vivir, trabajar, descansar, adaptándose a lo que venía de vuelta en vuelta ofrecido por las ciudades. Frecuentemente la población se organizó para remediar, incluso ilegalmente, a las decisiones o las no-decisiones de las públicas administraciones, yendo así a diseñar un sistema territorial que es cada vez más difuso e menos poli céntrico que pero se caracteriza por gravitar sobre las grandes áreas urbanas y para manifestar en modo cada vez más acentuado los caracteres de mono funcionalidad difícilmente manejable en términos de eficacia de servicios y equipamientos públicos. Esta investigación sobre la periferia italiana y en particular romana se desarrolló utilizando técnicas de diagnósticos tradicionales soporte de ayuda de medios innovadores que ahora entraron a formar parte de las herramientas del urbanista: fotos satelitales, videos, internet. El recurso a tales medios permitió poder seguir mejor las transformaciones del territorio mismo en vivo, permitiendo al mismo tiempo la comparación con distintas fuentes informativas. Técnicas y fuentes innovadoras que no pueden sustituir al hombre pero que pueden facilitar mucho el trabajo de los operadores del sector, incluso en términos didáctico y de difusión de los conocimientos. *** ENG: To talk about periphery today implies the need of reviewing the meaning of the word itself. “Border” seems to be the most appropriate definition to describe the contemporary periphery, being it applicable to all the low density settlements that, in the last decades, inexorably surrounded big cities - and, unfortunately, not only those - occupying territories that generally used to be for agriculture. A periphery that is characterized basically for being “incomplete”, as a natural consequence of the interruption of the processes, as much spontaneous as planned, that produced it. The Roman scene is an extensive collector of peripheries, different and non homogenous, generally deteriorated, born since the end of World War II and which are still growing, only partially according to a general urban plan. Nevertheless the spontaneous periphery shows almost always established characteristics of a “quality” that are little or totally present in those planned. They are heterogeneous peripheries mainly of illegal character that unite the substantial absence of public spaces for social relation, of “central places”, to a provisional state that stresses their character of periphery. The first peripheries were born from the “necessity” - to live, to work, and to rest - in a period when the public administration could not or did not want to address the problem of settlements; during the years, this model of settlements have consolidated and begun to replicate itself, dangerously changing its typical features until losing its character of “necessity”. The private house with garden far from downtown, has become one of the most diffuse desiderata of the last years, when the cities began to be polluted because of - in a vicious circle - the traffic generated by those living in the peripheries and obliged to reach downtown every day. People get used to live in these heterogeneous peripheries that combine the absence of spaces for social relation and a provisional state stressing the character of periphery. And they do not perceive the “absence of the city” as a major problem, but only ask for more services and better mobility, both public and private. In thirty years, the idea of living, city and periphery was transformed. But this phenomenon goes with a sensible decay of the quality of life and of the environment. There is a very strict relation between birth and diffusion of the peripheries and the beginning of the process, still in place, of urban diffusion and dispersion. The breakthrough point of the settlements tradition - that culture of old and almost universal origins that was transmitted probably orally of father in son and that was by all well-known – can be put by the end of the Sixties and beginning of the Seventies. A transformation that brings to a diffuse settlements of residential character, with very low density (less than 15 hab/ha and less than 1 m3/m2), connected to the main cities by means of some routes or, in the most lucky cases, of railway infrastructures ensuring the connections with the places of study, work and spare time. The patterns of living, working and resting changed and adapted to what was offered by the cities. Frequently, the population was ready to remedy, even illegally, to the decisions or the not-decisions of the public administrations, thus creating a territorial system that is more and more widespread and less polycentric, which is characterized for weighing on the great urban areas and for showing in a more and more marked way the characters of hardly manageable mono functionality in terms of effectiveness of services and public infrastructures. This investigation on the Italian, and in particular Roman , periphery was carried out by using techniques of traditional analysis together with innovative tools that are now considered of normal use for the city planner: photos satellite, videos, Internet. The use of such means allowed following the transformations of the territory better and in real time, at the same time allowing the comparison with different informative sources. These innovative techniques and sources cannot replace the human resource but can very much facilitate the work of the operators of the sector, also in terms of teaching and diffusion of knowledge.