04040nam 2200697 a 450 991097354950332120251116140828.0978030917408403091740829780309524070030952407597805851447950585144796(CKB)110986584752290(OCoLC)44963977(CaPaEBR)ebrary10041163(SSID)ssj0000152215(PQKBManifestationID)11136849(PQKBTitleCode)TC0000152215(PQKBWorkID)10339157(PQKB)11714860(MiAaPQ)EBC3375743(Au-PeEL)EBL3375743(CaPaEBR)ebr10041163(OCoLC)923258546(Perlego)4734052(BIP)53858324(BIP)47623507(EXLCZ)9911098658475229019980603d1998 uy 0engurcn|||||||||txtccrThe exploration of near-earth objects /Committee on Planetary and Lunar Exploration, Space Studies Board, Commission on Physical Sciences, Mathematics, and Applications, National Research Council1st ed.Washington, D.C. National Academy Press19981 online resource (44 p.) The compass seriesBibliographic Level Mode of Issuance: Monograph9780309060837 0309060834 Includes bibliographical references.Front Matter -- Foreword -- Preface -- Contents -- Executive Summary -- 1 Introduction to Near-Earth Objects -- 2 Status of Current Research Programs -- 3 Future Research Activities -- 4 Technological Aspects of Studies of Near-Earth Objects -- 5 Conclusions and Recommendations -- Glossary.Comets and asteroids are in some sense the fossils of the solar system. They have avoided most of the drastic physical processing that shaped the planets and thus represent more closely the properties of the primordial solar nebula. What processing has taken place is itself of interest in decoding the history of our solar neighborhood. Near-Earth objects are also of interest because one or more large ones have been blamed for the rare but devastating events that caused mass extinctions of species on our planet, as attested by recent excitement over the impending passage of asteroid 1997 XF11. The comets and asteroids whose orbits bring them close to Earth are clearly the most accessible to detailed investigation, both from the ground and from spacecraft. When nature kindly delivers the occasional asteroid to the surface of Earth as a meteorite, we can scrutinize it closely in the laboratory; a great deal of information about primordial chemical composition and primitive processes has been gleaned from such objects. This report reviews the current state of research on near-Earth objects and considers future directions. Attention is paid to the important interplay between ground-based investigations and spaceborne observation or sample collection and return. This is particularly timely since one U.S. spacecraft is already on its way to rendezvous with a near-Earth object, and two others plus a Japanese mission are being readied for launch. In addition to scientific issues, the report considers technologies that would enable further advances in capability and points out the possibilities for including near-Earth objects in any future expansion of human exploration beyond low Earth orbit.Compass series (Washington, D.C.)CometsMeteoroidsNear-earth asteroidsComets.Meteoroids.Near-earth asteroids.523.44MiAaPQMiAaPQMiAaPQBOOK9910973549503321The exploration of near-earth objects4365230UNINA