Phoenix AZ and Zagreb CR

Not much in the way of photographs taken today but when we spotted these two aircraft Ruby said the one coming towards us was going straight up into the sky. She meant 'like a rocket', but it was a bit of an optical illusion of course. 
Then the second one appeared going in exactly the opposite direction.
I looked at FlightRadar24 and it turned out that;
No. 1 - was headed for Phoenix, Arizona.
No. 2 - Headed for Zagreb.
I'm afraid I can't remember the departure airports but I think 2 was from Canada.