Planetário Professor José Baptista Pereira, Planetarium and museum in Porto Alegre, Brazil

Planetário Professor José Baptista Pereira is a flattened concrete cone with glass and aluminium frames, held by 14 exposed concrete beams, covering 1,040 m² with a basement. Inside, a 12.5-metre dome seats 120 people in a circle. The building stands at the corner of Avenida Ipiranga and Rua Ramiro Barcelos on the UFRGS Health Campus.

The planetarium resulted from a 1966 agreement between the city and UFRGS: the city built it, the university supplied the German-donated equipment. The building, designed by Fernando Gonzalez with Walter Bered, opened on 11 November 1972 during the XIII Semana de Porto Alegre. On 20 October 1972 NASA astronauts James Lovell and Donald Slayton visited and signed a concrete plaque. Vacilia Derenji was the first director.

The planetarium is named after José Baptista Pereira, a UFRGS engineering professor who first proposed its construction and founded the Associação Astronômica do Rio Grande do Sul. Its first director was Vacilia Derenji. In 2022 the exhibition Vivências marked 50 years, and the new projection dome was named after physicist Ary Nienow, a member of the first team who died in 2021.

Visitors do not need any special background knowledge, as the displays present basic astronomy concepts for all ages. The building is surrounded by gardens that guests can explore before or after their visit inside.

On 20 October 1972, before the official opening, NASA astronauts James Lovell, commander of Apollo 13, and Donald Slayton visited the unfinished planetarium; a concrete plaque bearing their signatures was installed there. The building's flattened cone shape, with 14 exposed concrete beams, is often compared to a spaceship.