2025-09-29, 05:43 PM
Hi Dennis,
The mount would need to know your location to point the telescope correctly, but you're right that it may not correct its NEO ephemeris calculation for the position on earth and just assume geocentric coordinates. That won't give accurate positions for close passes. What does SkyTools predict for positions if you use the geocentric option for the ephemeris calculations? Does it match what the mount's predicting? If so, that would confirm your supposition. Can you contact the manufacturer and ask about how they handle minor planet position calculations?
The MPC had 2025 SS5 at 0.27 LD at close approach.
Phil S.
The mount would need to know your location to point the telescope correctly, but you're right that it may not correct its NEO ephemeris calculation for the position on earth and just assume geocentric coordinates. That won't give accurate positions for close passes. What does SkyTools predict for positions if you use the geocentric option for the ephemeris calculations? Does it match what the mount's predicting? If so, that would confirm your supposition. Can you contact the manufacturer and ask about how they handle minor planet position calculations?
The MPC had 2025 SS5 at 0.27 LD at close approach.
Phil S.
![[-]](https://skyhound.com/forums/images/collapse.png)