Gobble, gobble, gobble, gobble, gobble.

And you just, literally, have to send little nuclear factories up there that gobble up the iron oxide on the surface of Mars and spit out the oxygen.

Nothing else ultimately explains lenders immense willingness, in the boom up to 2006, to lower their credit standards on home mortgages, regulators willingness to let them do it, rating agencies willingness to rate mortgage securities highly, and investors willingness to gobble them up.