I'm trying to retrieve the orbital elements' uncertainities for asteroids queried from NASA JPL Horizons. However I'm not able to find them in the query fields returned in python. Nor am I able to find any reference to individual uncertainites of respective orbital elements in the Horizons website. The desired uncertainites are to be used later to populate a clone of particles for an orbital integration simulation.

This seems to be straightforward, but I'm probably missing something.

Any ideas and help highly appreciated.

Thanks !


2 Answers 2


I think I found the answer after some search. What I have been after is the JPL Small-Body Database Browser. You can simply enter the object name to the search field and it returns a page where you will find the orbital uncertainities along with other useful data. For example, type in 'eros' and you will see the results. Of course, this can be automated in python thanks to the astroquery.jplsbdb module.

  • 2
    $\begingroup$ BTW, it's not hard to access Horizons via ssd.jpl.nasa.gov/horizons_batch.cgi just using the Requests module. See my script in astronomy.stackexchange.com/a/44903/16685 for an example. $\endgroup$
    – PM 2Ring
    Commented Aug 13, 2021 at 23:46
  • $\begingroup$ @PM2Ring Thanks for the link. However I ended up using the python module as it already returns data from sbdb, and I just need to extract the ['orbit']['elements'] part to obtain the six standard orbital parameters with their uncertainities. $\endgroup$
    – mysterium
    Commented Aug 19, 2021 at 16:17

NASA JPL HORIZONS returns a set of uncertainty parameters in full-precision HTML condition query ('-sigma' columns). Is that what you mean?

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    $\begingroup$ Does this work if someone uses the interface on the website? Can you show a screen shot or explain what " full-precision HTML condition query ('-sigma' columns)" means? If you have a clarifying question for the OP you can do that with a comment. This is an answer post, it's not a place to ask questions. Thanks! $\endgroup$
    – uhoh
    Commented Aug 13, 2021 at 13:58
  • $\begingroup$ Actually, it was done by a comment...Link is by OP, that's why I didn't weighted intended comment by a screenshot. $\endgroup$
    – Lariliss
    Commented Aug 13, 2021 at 15:35

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