- What is NEODyS?
- How NEODyS works
- Future expansion of NEODyS
What is NEODyS?
Fundamentally, NEODyS 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. (Comet orbits are planned for a future expansion.)
This site provides a number of services to the NEO community.
- For each NEO in our database, the results of our orbit
determination are available for inspection and comparison with
other sources. Everything needed by the user to verify our
computations is available online, including our
- Our observation prediction service provides ephemeris
predictions and finder charts with information on the linear or
confidence region as appropriate.
- Each object is linked to a database of known physical properties.
How NEODyS works
NEODyS is based on a
database running on a
The database of orbits is continually and automatically maintained
with the most recent
Minor Planet Center
observations. The orbits are computed with the
software package provided by the
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. Here are a few of the things
on our "To Do" list.
- 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
NEODyS is currently operated by a consortium with the following
, University of
Pisa, Italy (in particular the Celestial Mechanics
Milani Comparetti is one of the founders of
F. Gronchi, and
Tommei are active members.
- Giovanni B. Valsecchi is one of the founders
Alessio del Vigna after having worked to the system for several years in their previous
jobs at University of Pisa.
There are other institutions with which either we have a collaboration
which is important for the quality of the NEODyS service, or have
greatly contributed in the past to the development and operations of
- Jet Propulsion Laboratory, Pasadena (CA), USA
- Steve Chesley
is one of the founders of NEODyS. The NEODyS 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.
- 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:
srl, Cascina, Italy:
- Nicola Ronci and Raffaele
Guerriero have been major contributors in the development of
the original database and web interface for NEODyS. The
interface has now been replaced with one based upon the free
software PHP, but the basic ideas are the same.
- The members of this group of researchers have developed the
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 NEODyS, including the ones for impact monitoring,
are based on library routines from this package.
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