 a third floor , called " The Theatre of the Stars " , was devoted wholly to astronomical shows , and featured a Zeiss planetarium projector along with 85 slide and video projectors used to recreate starry skies , along with two back rooms that housed computers , cooling systems , and audio / visual controllers . The public theatre could seat 340 people at a time , and contained a sound system of approximately 25 @,@ 000 watts . 
