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  1. What is AstDyS?
  2. How does AstDyS work?
  3. Future expansion of AstDyS
  4. Credits

What is AstDyS?

Fundamentally, AstDyS provides information on numbered asteroids with a convenient Web-based interface. It is based on a continually and almost automatically maintained database of asteroid orbits. This site provides a number of useful services to the asteroid observers and scientists interested in studying them.

How does AstDyS work?

AstDyS is based on a Postgresql database running on a Linux system.

The database of orbits is continually and almost 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 AstDyS

AstDyS is continuously expanding and improving. Here are a few of the things on our long range "To Do" list.

How to get help?

Every page has a context sensitive "help" link at the top and bottom of the page. This is the place to look for an explanation of the data and terminology you see on a particular page.

We also provide answers to Frequently Asked Questions (FAQ).

If you still have questions, comments, complaints, or suggestions after reviewing this information please use the contact interface. We are always working to make this site more informative.


AstDyS is currently operated by a consortium with the following participing institutions:

Department of Mathematics , University of Pisa, Italy:in particular the Celestial Mechanics Group.
Andrea Milani Comparetti is one of the founders of AstDyS, Giovanni F. Gronchi, and Giacomo Tommei are active members.
IASF-INAF Rome, Italy:
Giovanni B. Valsecchi is one of the founders of AstDyS.
SpaceDyS srl, Cascina, Italy:
Fabrizio Bernardi, Alessia Bertolucci and Lisa Bedini are active members of AstDyS on behalf of their company.

There are other institutions with which either we have a collaboration which is important for the quality of the AstDyS service, or have greatly contributed in the past to the development and operations of the system:

Jet Propulsion Laboratory, Pasadena (CA), USA
Steve Chesley is one of the founders of AstDyS. The AstDyS automatic information system was developed by Steve while at the University of Pisa on a NATO-sponsored postdoctoral fellowship, under the supervision of Andrea. He wrote most of the Perl code that transfers the output of the Fortran programs into the database. Steve left the University of Pisa at the end of 1999 to work at the Jet Propulsion Laboratory. In his present position of responsible for the NASA SENTRY system he is still an essential collaborator, because of the requirement for technical verification of the most serious risk cases.
Astronomical Observatory of Belgrade, Serbia
Zoran Knezevic is the Director of the Astronomical Observatory of Belgrade. He is in charge of the computation of the proper elements of the asteroids, both analytic and synthetic.
Department of Astronomy at the Faculty of Mathematics, University of Belgrade, Serbia
Bojan Novakovic has developed the interface with the GRID distributed computing system for AstDyS.
Department of Applied Mathematics, University of Valladolid, Spain:
María Eugenia Sansaturio and Oscar Arratia have contributed important software segments and have also operated the system for a long time.

We would like also to acknowledge the following contributions:

Hyperborea srl, Cascina, Italy:
Nicola Ronci and Raffaele Guerriero have been major contributors in the development of the original database and web interface for AstDyS. The interface has now been replaced with one based upon the free software PHP, but the basic ideas are the same.
OrbFit Consortium
The members of this group of researchers have developed the OrbFit software system. OrbFit does many things, the most important ones being orbit propagation, orbit determination, observation prediction, close approach analysis, and orbit identification. All of the orbital computations done by AstDyS, including the ones for impact monitoring, are based on library routines from this package.