A New Disintegrative Capture Theory for the Origin of the Moon

TL;DR

This paper proposes a disintegrative capture theory for the Moon's origin, suggesting it formed from a captured proto-Moon at Earth's L4 point, challenging the giant impact hypothesis and aligning lunar formation with Earth's early life emergence.

Contribution

It introduces a novel capture-based model for the Moon's origin, explaining lunar features and age without requiring a giant impact collision.

Findings

The proto-Moon was captured from Earth's L4 point.

Tidal forces disintegrated the proto-Moon, depositing core material on Earth.

The remaining lunar material formed the current Moon, potentially only 3.8-3.9 billion years old.

Abstract

The object that resulted in the creation of the Moon started in the same orbital path as Earth around the Sun, but at Earth's L4. This proto-Moon (PM) was 4 times less massive than the usual Giant Impact (GI) object "Theia" and was captured into Earth orbit. It had a 32% Iron-Nickel-Sulfur core supporting a dynamo, which explains magnetized lunar rocks. Following capture, it was torn apart by tidal forces and its core of iron plastered itself, with some of its rock mantle, on the surface of Earth at a very flat angle (producing the "Late Veneer"). After tidal stripping, the remaining PM rock was driven away from Earth to about 3.8 times Earth's radius and formed into what is now the Moon. The GI theory has several troubles: The violent collision melts the entire Earth, contrary to geological evidence. The Moon itself also has to condense out of the vapor cloud generated in the collision, but there is evidence that the Moon was not condensed out of vapor. In the new theory, the Moon as we know it may be only 3.8 - 3.9 billion years old, not 4.56 as usually assumed. That is the age of the PM. The minerals in the Moon would be about as old as the Earth, but would have been re-arranged in the capture and temporary disintegration process. If the Moon is as young as suggested, its origin would coincide with the beginning of life on Earth, which is unexplained in the GI theory. The manuscript asks, "Was the Moon Turned Inside-Out" and the answer is "Essentially, Yes."