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
Rep. Alexandria Ocasio-Cortez’s stunning election win eight years ago heralded the start of a broader political shift, and the New York Democrat sees that swelling into a transformational movement. In an interview Sunday on ABC News’ This Week, she acknowledged that her party had lost support from young people in earlier election cycles, especially young
Twice each day, tides ebb and flow through a maze of sandy channels, mudflats, and mangrove forests that flank the 88 islands and islets of Guinea-Bissau’s Bijagós Archipelago (Arquipélago dos Bijagós in Portuguese). Seen from above in this image from Nov. 28, 2025, the process leads to stark changes to the landscape: around low tide, intertidal mudflats and sandflats
