the calculus of the ephemerides of the searched object, allowing three options for the input which are offered as three different pages linked from the main EURONEAR Data Mining Tools[^19]. Moreover, additionally to the standard web form, the actual [*Mega-Precovery*]{} v.3 allows programmable queries via HTTP commands.

### Mega-Precovery from Designations

This is our first classic search for one or a few known asteroids or comets, based on the name, number or designation [^20]. The user can chose between two ephemerides generators, either using the classic Miriade server[^21] [@Berthier2009] (available in [*Mega-Precovery*]{} v.1, v.2 and v.3) or the [*OrbFit*]{}[^22] software [@OrbFit2011] installed only in [*Mega-Precovery*]{} v.3. The SsODNet service at IMCCE[^23] [@Berthier2007] is used to check object designations.

### Mega-Precovery from Orbit

If the object doesn’t have an official name, number or designation, but its orbital elements are know, then these can be input into Mega-Precovery[^24]. The required elements are the semimajor axis $a$, the eccentricity $e$, the inclination $i$, the ascending node $\Omega$, the argument of periapsis $\omega$, the mean anomaly $M$, and the epoch $MJD$.

### Mega-Precovery from Observations

If the object was discovered very recently or if the connection with the ephemerides server is broken, then the 