Since time immemorial, or at the very least the mid 90s, the MPC has been providing asteroid orbits via MPCORB.DAT, a fixed-width text file like the ones your grandpa used to load into his Fortran routines. But time moves on relentlessly, and a new generation of programmers and developers expect data to be delivered in modern formats such as JSON (which has been in use since the early 2000s, we might add). To satisfy this need we have embarked on a voyage on conversion and now offer some of our most used files in JSON format, while still offering the classic fixed-width format files unchanged.
Seizing the opportunity the JSON conversion provided, it was decided that extra information could be added to that in the classic files, and so the concept of “extended” files was born. These extended files are offered in both fixed-width and JSON format. To the fixed-width versions we’ve added, at the end of each line, the Time of Perihelion, and a list of all provisional designations (in unpacked form!) associated with that object. To the JSON versions, in addition to this, we’ve also added other useful data such as perihelion/aphelion distances, synodic periods, etc. Thanks to JSON’s flexibility we expect to add more data in the coming months (such as ΔV, discovery date, etc.).
To make it easier to navigate the large amount of data files the MPC provides, we’ve created a new section of the site called, appropriately, Data. It is now a tab in the top menu, which will take you directly to the page listing the data files, with a brief explanation of their content, their update frequency, and the documentation explaining the contents and their format (which was written especially for the occasion).
Without further ado, here be the portal to the MPC’s data files:
The list will grow over the coming weeks, and we hope to add a new column with the date/time each file was last updated, as well as making the table sortable. Stay tuned!
Please send comments and suggestions to J.L. Galache (or leave a public comment below).