With all do respect to some who are stuck on the circles, I think the point is about the info, the time sent, etc.
I think the answer is sort of basic considering the source (Carl Sagan) and that is simply; He just may have had info he knew was being withheld that
could benefit mankind, and in his wisdom knew that "in time" other scientists would understand he didn't make an error and the number of DNA pairs
would eventually be known. At such a time, many others would also be familiar enough and be able to piece together, that some of those in position
and/or power were, and most likely still keeping everyone in the dark. If he knew this info in 74, and we only officially found out a short time ago,
the same info; then how much more is known that would take us that much longer to find out and help mankind, or explore much more or who knows the
limits?
I'm glad someone took the time and stated this info in a way that in my opinion, really doesn't leave much to speculate on how much we're kept in
the dark and told it's not our business to know....Great work on the OP