"फलकम्:Infobox planet/doc" इत्यस्य संस्करणे भेदः

'''On orbital characteristics:''' The orbital circumference should be computed from the semi-major axis using [[Ellipse#Circumference|Ramanujan's approximation]] for ellipses. The ratio of that circumference to the period then gives the average orbital speed. The minimum and maximum speeds follow from Kepler's laws: <math>v_{max} = 2\pi a^2 \frac{\sqrt{1-e^2}}{T a (1-e)}</math> and <math>v_{min} = 2\pi a^2 \frac{\sqrt{1-e^2}}{T a (1+e)}</math>. Note that, by convention, all orbital parameters are given in the primocentric reference system (heliocentric for the planets).

 

 

'''On physical characteristics:''' The surface area and volume of non-spherical objects (e.g. moonlets, asteroids) must use the proper [[ellipsoid]] formulae, because even slight departures from sphericity will make a large difference, particularly for the area.