2021-11-16, 09:28 PM
(This post was last modified: 2021-11-16, 09:30 PM by bigmasterdrago.)
Yes, the MPC uses that format.
In the hyperbolic case, the only sensible way to label mean anomalies is from minus infinity to plus infinity, with zero being perihelion. Negative MAs are when the object is approaching and positive MAs are when the object is receding. I guess that most astronomical products don't have to worry about the hyperbolic case.
Mean anomalies don't indicate prograde or retrograde motion, however they're expressed. If you're interested in whether an object is prograde or retrograde, you need to look at the inclination. If it's less than 90 degrees it's prograde, and if it's more than 90 degrees it's retrograde.
In the hyperbolic case, the only sensible way to label mean anomalies is from minus infinity to plus infinity, with zero being perihelion. Negative MAs are when the object is approaching and positive MAs are when the object is receding. I guess that most astronomical products don't have to worry about the hyperbolic case.
Mean anomalies don't indicate prograde or retrograde motion, however they're expressed. If you're interested in whether an object is prograde or retrograde, you need to look at the inclination. If it's less than 90 degrees it's prograde, and if it's more than 90 degrees it's retrograde.