The `J_2` constant is the Earth's second dynamic form factor used in computing the `J_2` perturbation of the inverse square formulation of the gravitational effect on the force due to a perfect spherical body of uniform density.
The MATH AND SCIENCE
This factor can be calculated as:
`J_2 = (2 epsilon_E/3) - (R_E^3 omega_E^2) / (3 G M_E)`
where
REFERENCE
Equation section of Nodal Precession article
SEE ALSO