Formation of an Iron-Poor Moon by Partial Capture, or: Yet Another Exotic Theory of Lunar Origin
Abstract
It is shown how it is possible to explain the low abundance of iron and siderophiles in the Moon in a natural way. This is done by an extension of Öpik's mechanism, whereby one or more planetoids pass through Earth's Roche zone, are broken up, and have part of their material captured. Assuming the planetoids are differentiated, the iron core can easily escape capture. This process does not involve any dissipation mechanisms and goes a long way toward explaining the peculiar bulk composition of the Moon. The picture is consistent with that of Urey, in which the early solar system contained more (and smaller) planets than it does today. In the second part of the paper, dynamical considerations are applied for two models, and it is shown that capture from one (or a few) planetoids is quite feasible, whereas a large number of contributors is highly unlikely.
- Publication:
-
Icarus
- Pub Date:
- February 1975
- DOI:
- 10.1016/0019-1035(75)90102-5
- Bibcode:
- 1975Icar...24..256M
- Keywords:
-
- Abundance;
- Astronomical Models;
- Earth-Moon System;
- Lunar Composition;
- Lunar Evolution;
- Angular Momentum;
- Gravitational Effects;
- Iron;
- Roche Limit;
- Selenology;
- Lunar and Planetary Exploration, Earth Science;
- Earth Science