Sagan was on Carson about 38 times, so...
You and others would have been sure to catch him at least once or
twice even if by chance. Sagan owed a fair bit to Carson for making
him as publicly known as he was, though he did stick Sagan with that
"billions and billions" inaccuracy too, but such is the price of fame.
I remember one Sagan appearance where he humorously complained
about how Chewbacca did not receive a medal at the end of the very
first Star Wars like his two human(oid) companions did. Sagan said
that showed a very anti-Wookie sentiment. :^)
And again, how often do you see real scientists coming on talk shows
any more to discuss real science topics and new findings? Times have
definitely changed.