Out of focus

We went to Sweden to see the Northern Lights last year and we wanted to take pictures of them so we decided to rent the camera from a professional photographer of the northern lights, he set up the camera for us so that we could catch the lights. Every time we took a picture we would see in the screen if we it looked ok and it did but when we came back home and put it in the computer they were all out of focus. They look like we took pictures running. Am I able to fix this??? Help