This study aimed at describing the quality of astrophysics teaching and learning during the implementation of lesson study, including the students' activity and the impact of the lesson for improvement in students' learning outcome. The type of research was case study with descriptive qualitative analysis. The study was done in 3 cycles of Plan, Do and See. The subject was 3 lecturers in science education study program and the 4th semester students of Science Education Study Program Universities Education Ganesha. The data about learning activities and learning outcome was gathered during the learning process which is assessed from the observation sheet, interview and written questionnaire. Also, the students' learning outcome was gathered from the written test. The results showed that the lesson study was conducted in good category and the students' learning activity can be classified as active.

This study is a preliminary stage on development learning materials using inquiry model and PhET media to enhance junior high school students’ science process skills. The need assessment is aimed to give preliminary understanding in term of curriculum, learning theory, challenge and needs in the future. The data is gathered by observation, interview and documentation methods. Descriptive analysis had been chosen as the data analysis method. The result showed the following facts. First, the implementation of Curriculum 2013 with inquiry learning model and supported by PhET Media is necessary to improve the students’ science process skills. Second, the students need to have competencies in affective learning outcome, psychomotor skills, cognitive product and process skills. Third, the set of learning materials needed are including syllabus, lesson plan, students’ book, students’ worksheet and assessment sheet in density and buoyancy topic for the eight-grade junior high school students of SMP Lab Undiksha Singaraja.