GG: C major P & F, Book I or II?

[Michael Arnowitt <arnowitt@sover.net>]

Many years ago I recall reading that the C major Prelude and Fugue from
Bach's Well-Tempered Clavier was on a record that was sent by a NASA space
probe (Voyager? I get the various names mixed up) sometime in the 70's.
This probe took advantage of a quirk of planetary alignments in to generate
a trajectory that would enable it to rocket out of our solar system into
deep space.  A record was created with different samples of world music
(folk, classical, and jazz).  This record, along with a record player and
instructions on how to operate it, was placed in the contents of the
spaceprobe in case intelligent life ever found it.

Since Glenn's recording of the C major P & F from Book I is so famous, and
the piece so well-known, I always assumed that was what was put on the
recording.  But a few years ago I *thought* I remembered reading that it was
actually the C major from Book II of the Well-Tempered Clavier that was on
the record.  Anybody have knowledge of this?  I happen to love this piece,
but I do wonder why it was chosen.  The Book I would have been such an
obvious choice (it's well known due to the Ave Maria connection), and so
someone from NASA who chose the one from Book II would have to have been
pretty knowledgable about classical music, unless I'm misremembering the
whole thing and it was the one from Book I.

Michael