 Starting in 1978 , there was a decline in attendance that lasted for four years while major construction was being undertaken at its sibling institution , the adjacent Royal Ontario Museum . This work also entailed the demolition of part of the planetarium 's facilities . Though attendance picked up when the museum reopened in 1984 , the planetarium was forced to close on November 5 , 1995 , due to provincial budget cuts to the museum . The planetarium 's exhibits , artifacts and theatre facilities were subsequently dismantled and dispersed . For a brief period it housed the Children 's Own Museum . It is now used solely for offices and as a storage facility for the museum . 
