Earth: Day Zero • Paper 067 of 512

Lunar Mass Constraints

One of the strongest Earth–Moon system observations is the mass of the Moon itself.

Any proposed Day Zero framework must account for the existence of a satellite possessing approximately 1.2% of Earth's mass.

Constraint Significance

Mass represents a quantitative observation rather than a qualitative interpretation.

Consequently, lunar mass functions as a powerful boundary condition on possible reconstruction models.

Model Independence

The constraint exists regardless of the mechanism ultimately favored.

The question is not how the Moon formed, but whether the proposed reconstruction remains compatible with its existence.