登入選單
返回Google圖書搜尋
Near Earth Objects, Our Celestial Neighbors (IAU S236)
International Astronomical Union. Symposium
其他書名
Opportunity and Risk
出版Cambridge University Press, 2007-05-24
主題Science / Space Science / Astronomy
ISBN05218634579780521863452
URLhttp://books.google.com.hk/books?id=QQx8r1_TPQEC&hl=&source=gbs_api
EBookSAMPLE
註釋Near Earth Objects (NEOs), asteroids and comets, are the closest neighbors of the Earth-Moon system. They allow research not yet possible on more distant bodies. The IAU Symposium 236 focused on the specific observation and modeling techniques for NEOs, including radar, exploration by spacecraft, measurement of non-gravitational perturbations; also on the next generation surveys expected to increase a hundred-fold the NEO discovery rate. With data from first generation NEO surveys, we now understand how they formed and evolve, dynamically and physically, opening a window on the universal astrophysical phenomenon of collision, leaving clear markings on the surfaces of planets, including the Earth. NEOs with orbits crossing that of the Earth are also a source of impact risks and potential NEO collisions with the Earth represent a long term threat. Mankind has to put in place a chain of mitigating actions; NEO astronomers have successfully put in place the first link.