I was beaten to the Bonzo's above! However, for a comic song why not look at the stuff by Christine Lavin. The following are a few titles (and comments) from her web page.

"If We Had No Moon" (a studio version of this will be released later this year on an album produced by the National Space Society).

I Want To Be The First Folk Singer On The Space Shuttle

"Planet X" was inspired by an article I read about the plight of Pluto - is it or is it not a planet? The album begins by looking at the moon, ends gazing up at the whole big sky, and in between looks at life on this planet as experienced in the late 1990s.

Cheers Rana