NEODyS
Encyclopedia
NEODyS 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.
The database of orbits is continually and automatically maintained with the most recent Minor Planet Center observations. The orbits are computed with the OrbFit software package provided by the OrbFit Consortium. All of the computational services provided by this site can also be done with this software package.
. This allows a more flexible and easy to update system. In the same period the system switched to the new version of the Fortran 95 code OrbFit 4.0.
(Dep. of mathematics, University of Pisa, Italy), Maria Eugenia Sansaturio(E.T.S. de Ingenieros Industriales, University of Valladolid, Spain), Oscar Arratia(University of Valladolid), Fabrizio Bernardi
(IASF-INAF, Rome, Italy),
Giovanni F. Gronchi(University of Pisa, Italy), Giovanni B. Valsecchi(IASF-INAF, Rome, Italy), Giacomo Tommei (University of Pisa, Italy).
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 magnitudeAbsolute magnitudeAbsolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
(H) brighter than 25 but which are virtually lost, being their orbit too uncertain; and "Small", objects with an absolute magnitudeAbsolute magnitudeAbsolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
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, airmassAirmassIn astronomy, air mass is the optical path length through Earth’s atmosphere for light from a celestial source. As it passes through the atmosphere, light is attenuated by scattering and absorption; the more atmosphere through which it passes, the greater the attenuation. Consequently, celestial...
, solar and lunar elongation, phase anglePhase angle (astronomy)Phase angle in astronomical observations is the angle between the light incident onto an observed object and the light reflected from the object...
, 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 orbitOrbitIn physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
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 planetPlanetA planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s of the Solar SystemSolar SystemThe Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
. - Search: It provides the possibility of queries in the database according the orbital parameters or the observational conditions or the close approaches with the planetPlanetA planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s of the Solar SystemSolar SystemThe Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
. - 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
How NEODyS works
NEODyS is based on a Postgresql database running on a Linux system.The database of orbits is continually and automatically maintained with the most recent Minor Planet Center observations. The orbits are computed with the OrbFit software package provided by the OrbFit Consortium. All of the computational services provided by this site can also be done with this software package.
Future expansion of NEODyS
NEODyS is continually expanding and improving. The followings are the next tasks of the project:- Uncertainties of all the quantities provided with the orbit, e.g., MOID and absolute magnitude
- Variable time span for impact monitoring, based upon orbit uncertainty
- Inclusion of non-gravitational perturbations in the dynamic model
Major update
On February 5th 2009 NEODyS went through a major update of the system. A new web-interface is available running the free software PHPPHP
PHP is a general-purpose server-side scripting language originally designed for web development to produce dynamic web pages. For this purpose, PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document...
. This allows a more flexible and easy to update system. In the same period the system switched to the new version of the Fortran 95 code OrbFit 4.0.
The NEODyS team
The NEODyS team is composed by Andrea MilaniAndrea Milani (mathematician)
Andrea Milani Comparetti is an Italian mathematician based at Pisa University interested in topics as celestial mechanics, asteroids, Near Earth Objects , and the BepiColombo mission. Milani is an expert on asteroid impacts....
(Dep. of mathematics, University of Pisa, Italy), Maria Eugenia Sansaturio(E.T.S. de Ingenieros Industriales, University of Valladolid, Spain), Oscar Arratia(University of Valladolid), Fabrizio Bernardi
Fabrizio Bernardi
Fabrizio Bernardi is an astronomer.-Contributions:In October of 2001 he discovered an asteroid, proceeded by near earth objects : 2002 RQ25 3 , 2002 WP11 and the NEO 2003 FB5 Fabrizio Bernardi is an astronomer.-Contributions:In October of 2001 he discovered an asteroid, proceeded by near earth...
(IASF-INAF, Rome, Italy),
Giovanni F. Gronchi(University of Pisa, Italy), Giovanni B. Valsecchi(IASF-INAF, Rome, Italy), Giacomo Tommei (University of Pisa, Italy).