The Minor Planet Center, under the auspices of the InternationalAstronomical Union, is the clearing house for astrometric observationsof natural bodies within the solar system. Solar System surveyprojects, particularly those tasked with detecting and tracking NEOs,in the course of routine operations, also frequently collectobservations of artificial satellites on distant, "multi-day"geocentric orbits. The astrometric data on artificial satellites, whenrecognized as such, will be removed from MPC distributed holdings fornatural objects. The observations of artificial satellites originatingfrom participating observatories or their organizations that opt-inthat their observations can be made available for space situationalawareness purposes will be provided via a controlled distributionmethod to agencies and institutions recognized internationally forproviding information for a space safety purpose.
The Minor Planet Center (MPC) posts submitted observations to the NEOConfirmation Page when they have a high probability of being anunknown NEO, facilitating followup by the NEO community. The MPCactively removes from the NEOCP those tracklets whose motion can bematched with the two-line element set (TLE) of a known artificialobject.
A number of the tracklets submitted to the NEOCP cannot be activelymatched to a known artificial object, yet have such high rates ofmotion and such strongly geocentric orbits that there is a very highprobability that such tracklets correspond to artificial objects.
The submitted tracklet is flagged as potentially being artificial ("S") when the score (geoscore) for the object having a geocentric orbit is greater than 10. If any subsequent follow-up decreases the geoscore such that this criteria is no longer met, the object is automatically unflagged.
Any tracklet flagged as potentially artificial that is subsequentlyidentified with a known satellite (e.g. via match with a TLE) will beimmediately removed from the NEOCP.
Any tracklet flagged as potentially artificial that remains on theNEOCP will be removed automatically on an accelerated basis. The timefor removal depends on the geoscore and the 1-sigma positionaluncertainty ('unc', in arcmin). The object will be removed from NEOCPafter the following time elapses:
The time elapses are from the last observations processed.
Values for the geoscore and sky-plane uncertainties are currentlyderived fromJPL
On May 26th 2021, the MPC will implement the above-described flagging of suspected artificial objects. To demonstrate the format of the data once flagging commences, we provide the following examples.
N.B. The above examples are static files to illustrate the format and arenot updated in sync with the NEOCP.