The purpose of this study was to examine the effectiveness of astronomy activities in science education with preschool children through semi-structured interviews. The interviews were conducted with the children before and after the implementation of the activities. Five activities about astronomy were conducted for five weeks in practice. A total of 15 preschool children (seven boys and eight girls) in the age range from 60 to 72 months participated in the study. Semi-structured interviews were individually conducted, digitally recorded, transcribed, and analyzed by the researchers of the study. The related data were collected by semi-structured interviews prepared by the researchers of the study. It was revealed that the preschool children were curious about the "Discovery of the Sky" subject. They were interested and enthusiastic to learn the subject matter, and they were positively affected by the practices. It has been concluded that new concepts related to the subject of "Discovery of the Sky" have developed by using different methods and techniques.