Magnetopause Standoff Distances from Pressure Balance: A Six-Planet Test Against Measured Boundaries

This paper computes magnetopause standoff distances from pressure balance from stated published inputs, using algebraic relations whose every step is deposited as executable code. Across the cases computed, Psw nPa spans 1.50e-03 to 16. The first case gives body Mercury; standoff Rp 0.99; standoff km 2417; observed Rp 1.45; residual pct -31.7; B0 nT 195; Psw nPa 16. The last case gives body Neptune; standoff Rp 19.3; standoff km 475676; observed Rp 24; residual pct -19.5; B0 nT 1.40e+04; Psw nPa 1.50e-03. The calculations are simulated and computed from the stated assumptions; they are not measurements. Where a comparison against the Aldred Limit density bound is made, the bound values used are 9.72e54 g per cubic centimetre for a neutron carrier and 2.87e48 g per cubic centimetre for an electron carrier, and the size of any separation found is reported plainly, including where the result is that the bound does not constrain the magnetospheric quantity in question.