Astrometry Data Exchange Standard. Describes how information can be formatted to allow position and brightness information of an astronomical object to be stored in for instance, a simple text file. Supersedes and is more flexible than the previous format used by the Minor Planet Center, known as the 80-column MPC1992 format. See the MPC's July 2018 ADES announcement and their ADES Data submission page, together with the Concise Description of the ADES standard document.


Base-62 is used by the MPC to encode numbers, reducing the amount of characters required to store information.

Base-62 encoded text consists of numbers 0-9 and characters A-Z and a-z only, i.e. the characters "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", to represent "digits" 0 through 61. For example, Base-62 "007C" equals decimal 446 (since "007C" = 0*62*62*62 + 0*62*62 + 7*62 + 12 = 446).


The Minor Planet Center (MPC) is the single worldwide location for receipt and distribution of positional measurements of minor planets, comets and outer irregular natural satellites of the major planets.



A format for storing astrometry data, defined by the Minor Planet Center in 1992 and still in use today, though gradually being replaced by the ADES format. Individual lines are limited to a length of 80 characters.


Minor Planet Center Electronic Circular. See and

ObsID or Observation ID

A block of text, 25 characters long, generated by the MPC when astrometry observations are submitted to them. An ObsID is one of the primary inputs supported by the MPC's WAMO service.

An ObsID contains various sub-fields, all are base-62 encoded, start and end positions being:

1-3=Submission Date in YYYYMMDD format

4-6=Submission Time in HHMMSS format

7-8=Submission Milliseconds 0-999

9-16=Counter that increases for each submission

17-18=Sub-batch number within the main batch, usually = 1

19-25=Counter for the observation number within the sub-batch

An example Observation ID is La01fB000000F0yM010000001.


An acronym used by the Minor Planet Center for their 'Where Are My Observations?' service. See

Created with the Personal Edition of HelpNDoc: Make your documentation accessible on any device with HelpNDoc