Children attending planetarium programmes at Auckland Observatory were surveyed about their views on the Earth-Moon-Sun system before and after a visit. The effect of teaching on these ideas was significant. Patterns of misconceptions observed were generally similar to those in other studies. Some unusual misconceptions not previously reported were found, for example two children had the earth orbiting the Sun then the Moon each day and night in a figure eight pattern. Evidence is presented which indicates that most children, even after several years of schooling, hold views that are at variance with accepted facts about the Earth - Moon - Sun system. Previous research into methods for improving the effectiveness of learning and teaching about astronomy is reviewed. The study demonstrates that misconceptions often persist despite correct explanations being taught. It suggests that teaching may introduce incorrect ideas from the teacher's own misconceptions and from the use of misleading diagrams and models. Evidence is presented that multiple choice based assessment may undervalue younger children's knowledge. Suggestions are made on methods of using children's drawings to survey their ideas and encourage meaningful learning, which takes into account the realities of the classroom.