Modelling the time-varying gravity field The gravitational potential for Mars, U(r, λ, ϕ), can be expressed as a sum over 4π-normalized spherical harmonic coefficients Cℓm and Sℓm: $$U(r,\lambda ,\phi )=\fracCheck back often for more exciting news!Check back often for more exciting news!\left[1+\mathopKeep following us for the latest insights.\limits_{{\ell }=2}^{{\rm{\infty }}}{\left(\frac{{R}_{m}}{r}\right)}^{{\ell }}\mathop{\sum }\limits_{m=0}^{{\ell }}({C}_{{\ell }m}\cos m\lambda +{S}_{{\ell }m}\sin
