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Geologia Planetária: o planeta Terra como modelo análogo para o estudo de corpos planetários

Authors:
  • Curtin University

Abstract

Avanços tecnológicos recentes vinculados a exploração espacial permitiram a aquisição de dados anteriormente tidos como inacessíveis. Missões espaciais recentes realizadas pela Agência Espacial Norte-Americana (NASA) e Agência Espacial Européia (ESA), focadas principalmente na Lua, Marte, Júpiter, Saturno e Plutão, forneceram informações que permitiram incontáveis avanços na compreensão dos processos geológicos atuantes nos planetas e luas do Sistema Solar, bem como em corpos planetários em geral (i.e. cometas e asteróides). Interpretações dos dados obtidos embasaram-se sobretudo em modelos gerados a partir de processos análogos observados na Terra, extrapolados para os diversos contextos geológicos dos outros astros. Em todos os casos, partiu-se do pressuposto de que os modelos terráqueos podem ser aplicados, desde que sejam feitas as devidas correções para os efeitos das diferenças térmicas, de massa, composição atmosférica, crustal, mantélica etc. Em inúmeros casos, tal correlação mostrou-se possível. Porém, diversas das situações encontradas não podem ser explicadas tomando-se como base unicamente a Terra, exigindo a elaboração de novos modelos e constante adaptação por parte dos cientistas. Além disso, o atual nível de avanço tecnológico impossibilita a comprovação prática de várias das teorias e hipóteses geradas. Logo, interpretações geológicas acerca de outros astros devem ser consideradas apenas como suposições e hipóteses a respeito das escalas dos processos, fornecendo panoramas gerais a despeito dos processos atuantes e nunca quantificações exatas. Modelos gerados são, via de regra, balizados em modelos análogos desenvolvidos para a Terra, e consequentemente limitados pelo conhecimento dos processos diretamente observáveis na natureza que nos cerca. Consequentemente, feições similares são interpretadas como geradas por processos similares, fato que não necessariamente é verídico em outros ambientes. Nesse contexto, a correta avaliação dos limites interpretativos das informações obtidas faz-se essencial, não só para assegurar a correta aplicação do método científico como para evitar a supervalorização de linhas de raciocínio pouco ou não embasadas, que podem vir a resultar em afirmações infundadas e equívocos científicos diversos. Os estudos de caso analisado demonstraram perfeita compreensão dessas limitações, definindo com clareza as limitações metodológicas e de aplicação das conclusões alcançadas. Missões futuras prometem fornecer quantidades progressivamente maiores de dados, impactando ainda mais a forma como vemos o Universo.
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... Analogamente, essa definição pode ser aplicada para outros astros, como a Lua e Marte, configurando uma ferramenta poderosa para aquisição de dados científicos dentro das Ciências Planetárias(BAKER 2014, BRANCO 2016.Os dados de sensoriamento remoto são gerados a partir da interpretação das emissões eletromagnéticas coletadas a partir de um objeto ou região da superfície de um astro. Diversas técnicas são usadas para essa interpretação, extraindo informações valiosas a partir de dados brutos (i.e. ...
Thesis
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This textbook is intended to be used in a lecture course for college students majoring in the Earth Sciences. Planetary Science provides an opportunity for these students to apply a wide range of subject matter pertaining to the Earth to the study of other planets of the solar system and their principal satellites. As a result, students gain a wider perspective of the different worlds that are accessible to us and they are led to recognize the Earth as the only oasis in space where we can live without life-support systems. The subject matter is presented in 24 chapters that lead the reader through the solar system starting with historical perspectives on space exploration and the development of the scientific method. The presentations concerning the planets and their satellites emphasize that their origin and subsequent evolution can be explained by applications of certain basic principles of physics, chemistry, and celestial mechanics and that the surface features of the solid bodies in the solar system can be interpreted by means of the principles of geology. •Organized in a hierarchical manner so that every chapter builds on preceding ones •Abundantly illustrated with diagrams and color images •Includes problem sets and a glossary.