PAPER 3 OF THE LEF SERIES
LEF Mechanism in Practice
Pressure and the pear: building the Moon from within and from without
Abstract
In the LEF model the Moon was built from Earth material while still attached to it, by one process acting in two ways. From within, deep hot melt driven by internal pressure fed a rising body. From without, the Earth's light outer shell rose with a pear-shaped bulge and slid to its tip, where it became the body's skin and later the Moon's far-side crust. A one-dimensional pressure test gives a source pressure of 150.26 GPa. Lifting melt of 3,500 kg/m³ to the corotation radius costs 139.78 GPa, so the feed passes for melt lighter than about 3,864 kg/m³. A joint test of pressure head, flow resistance and radial load shows that a narrow passage cannot build the Moon. Balance requires a passage radius above about 1,000 km, holding 0.46 lunar masses and carrying a lateral load of order 10^22 N. The connection is therefore broad, hot and massive: a single pear of the Earth's own material, 9,000–11,000 km wide at the surface, with its tip 6,000 km wide at the start and 3,000 km at release. The body on the tip rises as a squashed dome, rounds, flattens with the spin and rounds again. Its contact, peeled annulus and upper dome become the near-side cap, a belt and the far side. When its centre of mass reaches the corotation line, about 17,287 km at latitude 22.5°, it separates and is released about 210 km beyond, on a nearly circular orbit. The pear lies inside the line and is gathered back into the Earth. The paper sets quantitative constraints on geometry, rheology and the division of mass.
Keywords: Moon; lunar origin; magma transport; source pressure; corotation radius; lunar crust; far side; Earth–Moon connection
How to cite
Duran, Z. (2026). LEF Mechanism in Practice: Pressure and the pear: building the Moon from within and from without. Paper 3 of the LEF series. https://lef-model.com/paper03.html