2026 Starry Sky Full-Day Course at Kawaguchi City Science Museum (川口市立科学館, Science World)

Kawaguchi City Science Museum (川口市立科学館, Science World) has a rooftop observatory equipped with a 65cm reflecting telescope (one of the largest in the greater Tokyo area) and holds night observation sessions on the 2nd and 4th Saturdays. Each session runs about an hour from sunset, with check-in starting 30 minutes before, a capacity of 50 people, and free admission. Advance reservation is via the application form on the museum's website. Sessions are canceled in bad weather (cloudy, rain, or strong wind); whether it proceeds is decided at 17:15 that day (17:00 in winter).