Frequently Asked Questions

astorbDB is a database of orbital elements and observed physical properties (when available) for all known minor planets in the Solar System. This database is built upon astorb, which has been supported by Lowell Observatory as a resource to the community for many years. The next generation astorbDB will see many improvements in the coming years including a number of novel tools that access and interface with the database. More information on astorbDB can be found on this page and here

As of early 2017 no physical properties are externally accessible in the database. Eventually we will include properties such as spectral types, rotation periods, lightcurve amplitudes, albedo, and broadband colors. As we start to ingest these data from various sources, we will summarize the state of physical properties in the database in an amazing table somewhere on this site.

Absolutely. As we modify and upgrade the underlying database that supports astorbDB we will continue to support the heritage flat ascii version of the astorb.dat file. This file can be accessed here.

These systems each maintain catalogs of independently calculated orbital elements for every minor planet in the Solar System. These calculations are performed with different fitting algorithms and error analysis methods. Each of these systems has particular strengths. The Minor Planet Center is the world's central clearing house for all minor planet astrometric observations and links individual observations to specific objects. Both JPL and Lowell rely on the MPC to collate and produce this master catalog of observations. JPL specializes in producing orbit solutions of the highest possible quality. astorbDB is designed to facilitate access to a comprehensive catalog of observed physical properties compiled from numerous sources. Coupling this with the underlying orbital elements will enable identification of science targets for follow-up observational studies.


Each month, after full moon, we download a monthy update from the Minor Planet Center which contains all asteroid observations, orbits, and cross references. For new objects, existing objects with new observations, and new linkages, we recompute the orbit using our locally written software and using custom procedures for removing outliers. Errors on the orbital elements are computed based on the formalism of Muinonen & Bowell (1993, Icarus 104, 255-279). All orbit fits are published to the astorb.dat file.

See our dedicated page for analytical asteroid dynamical type definitions here.

To send feedback or in the event of bugs or problems with the site, please send an email to asteroid@lowell

We have invested a lot of effort to make sure this database is as current as possible. As new NEOs, Centaurs, and TNOs are discovered and MPEC'd, we add their orbital elements to the database within 5 minutes. Currently (circa 2017) we ingest and update the orbits of all objects every month. The physical properties are more complicated and are updated at different cadences depending on the source of the data.

astorb originated at Lowell Observatory and has heritage that dates back to the 1970's. Since then it has largely been supported by the observatory with development and maintenance of the system attributed to a number of individuals including Ted Bowell, Lawrence Wasserman, Karri Muinonen, and Bruce Koehn. In 2016 specific support for modernizing and augmenting astorb was awarded by NASA through the PDART program. This will result in major improvements to the database and website in the coming years. This new work is being carried out by Nick Moskovitz, Brian Burt, Robert Schottland, Larry Wasserman, and Mark Bailen (USGS).

The next few years will see many changes to the astorbDB system. This will include augmenting the database with physical properties, creating new tools to facilitate observational planning, providing interfaces to enable complex queries of the database, and building a portal for community interaction with the database that will enable real time dissemination of observational results. You can check the updates page for the most recent changes.

We love all planets, major or minor, here at Lowell Observatory. However, we made the decision to start the modernization and augmentation of the database with a particular focus on asteroids. They are simpler in many ways, and it is our hope that the lessons we learn from developing astorbDB for asteroids can be applied to future development of an analogous cometary orbital and physical property database.

Any further inquries can be directed to