Compute semi-major axis from period (T) and mass

An object's semi-major axis can be computed from its period and the mass of the body it orbits using the following formula:

a is the semi-major axis of the object

T is the orbital period

G is the gravitational constant

M is the mass of the parent body

	Default units	Acceptable substitute units
a	meters (m)	kilometers (km), Earth radii (Re), Solar radii (Rs), astronomical units (AU), light years (ly), parsec (pc)
T	seconds (s)	minutes (m), hours (h), days (d), years (yr)
G	N m²kg^-2
M	kilograms (kg)	grams (g), Earth masses (Me), Solar masses (Ms)