Can pets read human emotions?

I firmly believe that animals can sense their masters emotions, especially when they are upset. I remember one of our dogs that we had at the time of my father's death name Rocky. My mother was sitting in a chair in the living room crying, and he went over to put his head on her knee as if to comfort her. Then I had a personal situation with the dog we acquired after Rocky by the name of Oso. I was in the room with him and he was lying on the floor, I was upset and crying over something that had just happened. He jumped up and started to lick my face as if to tell me everything was going to be all right.