I love this!
Two conflicting theories about the formation of the Moon.
It just goes to show that if you don't observe it actually happening, or you
can't reproduce it in a laboratory then there is no such thing as the LAST WORD
from the propagators for or adherents to a pair of conflicting scientific theories.

I'm going to quote almost verbatim below; but I will underline my take on it.

"The current theory about the Moon's origins is that it formed from debris
from a collision between Earth and another planet-sized body."

That theory is about 20-30 years old.

"But this has too many problems, according to Peter Noerdlinger
at Saint Mary's University in Halifax, Canada."

I'm not sure if Peter Noerdlinger is a professor or a postgraduate student. I'll find his SMU URL.

"The collision has to be implausibly gentle," says Noerdlinger. "You practically need someone to hold
a Mars-sized object just above the Earth and drop it, to avoid messing up Earth's orbit."

My take on what Noerdlinger almost hinted at is that the Lunar-formation theory allegedly involving a planetary collision
with Earth would require far too many....coincidences...i.e., far too many circumstances & coincidences that involve the right size, right mass at the right time, at the right impact angle, at just the right velocity....I agree!

"Noerdlinger prefers the theory [his?] that Earth and its Moon formed themselves out of the same gas cloud.
But critics of that theory say it does not explain why Earth formed an iron core while the Moon did not."

OK! Noerdlinger's critics have a point, so how does Noerdlinger respond to his theory's critics?

"Noerdlinger counters by saying that the 'proto-moon' did have an iron-core, but then Earth's gravity pulled
the iron-core to Earth, leaving behind a rocky shell which reassembled into our iron-free [iron-defficient?]
Moon."

Hmmmmm...With tongue planted firmly-in-cheek my favorite theory of Lunar formation belongs to an anonymous scientist, some 20-30 years ago, who said the Moon shouldn't exist with what we know about it...Good argument
to send more robots and men back to the Moon.

Jacob