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NEODyS (Near Earth Objects Dynamic Site) is an Italian and Spanish service that provides information on Near Earth Objects with a convenient Web-based interface. It is based on a continually and (almost) automatically maintained database of near earth asteroid orbits. This site provides a number of services to the NEO community. The main service is an impact monitoring system (CLOMON2) of all near-Earth asteroids covering a period until the year 2100. ==Services== * Risk Page: The most important service is the production of a Risk Page where all NEOs with probabilities of hitting the Earth greater of 10−11 from now until 2100 are shown in a Risk list. In the table of the Risk list the NEOs are divided into "Special", as it is the case of (99942) Apophis; "Observable", objects which are presently observable and which critically need a follow up in order to improve their orbit; "Possible recovery", objects which are not visible at present, but which are possible to recover in the next future; "Lost", objects which have an absolute magnitude (H) brighter than 25 but which are virtually lost, being their orbit too uncertain; and "Small", objects with an absolute magnitude fainter than 25 and, even if they are "lost", they are considered too small to result in heavy damage on the ground. Each object has its own Impactor Table (IT) which shows many parameters useful to determine the risk assessment. *Ephemerides: It provides ephemerides of the object, that is position on sky, V magnitude, altitude, airmass, solar and lunar elongation, phase angle, galactic coordinates, R distance to the Sun, delta distance to the Earth, motion on sky, and the uncertainty on sky. *Observation prediction: It provides the position of the object at a specific time, information useful for the observer and a graph showing the uncertainty on sky. *Orbital Information: It provides the dynamical parameters of the orbit of the object. *MOID: It shows the analysis of the Minimum Orbital Intersection Distance (MOID) of the object. *Proper elements: It shows the secular properties of the object. *Observational Information: It provides data of both optical and radar observations and their statistical performance. *Close approaches: It provides a table with all the close approaches until 2100 with the planets of the Solar System. *Search: It provides the possibility of queries in the database according to the orbital parameters or the observational conditions or the close approaches with the planets of the Solar System. *Observatories: It is possible to access the information regarding observatories and their performances. *Other services: Physical Information provided by the European Asteroid Research Node (E.A.R.N.); Orbit animation provided by the NEO Program Office at the Jet Propulsion Laboratory 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「NEODyS」の詳細全文を読む スポンサード リンク
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