I had the thrill to meet Cronkite purely by accident in the mid 1990s on a trip to Moscow.
I was visiting my sister who was working there and we went to dinner at the Slavonskaya hotel owned at the time by Raddison.  As I looked around the restaurant I noticed him sitting at a table with another man. 
Normally I never bother well known people in public, but c'mon this was Walter.
I went over to his table and introduced myself.
When I told him I was a newsguy he became instantly engaged.. wanted to know why I was in Moscow, what I was working on etc.  I told him I was actually visiting my sister who was working as a journalist too.  She came over and we both kept talking to him.
He was affable and actually kept talking until his friend actually had to say to him, hey Walter we really have to go now and pulled him away.
He told me he was in Moscow to film a documentary on the Russian space program.
I never knew which one he meant.
unfortunately these were the days before selfies... so I don't have one.