From: Lance Purple <lpurple@netcom.com>
Newsgroups: soc.history.what-if, rec.arts.sf.science
Subject: Re: Post script to "Moon out of Green Cheese"
Date:
        

[...] My question was, "How is this going to affect the size of the moon?" Assuming that the same mass of moon is changed into green cheese and assuming that Cheese is less dense than "moon" there is going to be a rather larger moon there. [...] The upshot of all of this is that the Cheese-moon radius will have to be 45% larger to keep a "cheese-moon" of equivalent mass.

Hmm. OK, so we turn the Moon into 7x10^25g of green cheese. Now, the density of most cheeses is about 1 g/cm (one third as dense as moon-rock), so the Moon should initially bloat out to a new radius of 2600 km like you said.

BUT: what'll happen to the cheese down in the mantle, with the massive weight of hundreds of kilometers of cheese crushing it? It will quickly separate into water and casein, with the water rising up towards the surface and the denser casein being forced further downwards. The protein will almost immediately start to break down into simpler products like water, NH3, and carbon. If you add up the amino acids that make casein, you see that the bulk composition is something like C6 H11 O4 N. The most stable set of end-products would probably be 8H2O + C2H6 + N2 + 10C. I get that we start with about 2x10^24 moles of water plus about 2x10^23 "moles" of casein, and end up with:

1x10^24 moles of C 8x10^22g 100 km radius core
3x10^24 moles of water 2x10^23g 400 km deep oceans
2x10^23 moles of ethane 1x10^22g thick atmosphere
1x10^23 moles of N2 4x10^21g 100 km atmosphere

So unless I've made a big math mistake somewhere, the green cheese Moon would quickly evolve into a strange little Europa-like or Titan- like world, with a very dense graphite core, a thick atmosphere and deep oceans, and almost no leftover cheese. :( or :) ?

NOTES:

  1. "Green cheese" assumed to be Swiss Sapsago or Schabzeiger cheese.
  2. Basic Sapsago cheese composition is 40% water, 40% casein, and 10% fats/salt/other. Values from "Fundamentals of Dairy Science, 2nd Ed." by Webb, Johnson, and Alford.
  3. Casein amino-acid composition is mostly glutamic acid (25%), isoleucine and leucine(16%), proline(12%), and lysine(8%). Values from "Modern Dairy Products, 3rd Ed." by L. Lampert.