SAASTA acquired the Johannesburg Observatory in 2003 and is currently refurbishing this site to accommodate a multifaceted interactive science awareness facility with a specific focus on astronomy and engineering.

The first phase, which includes facilities such as science and computer laboratories, offices and space for indoor and outdoor exhibits, has been completed and the centre opened its doors to the public in 2008.

Programmes for learners, teachers and members of the public

Observatory Tour
The Observatory tour exposes the general public and learner visitors to different concepts of science and technology under the main themes of astronomy, astrophysics and optics through different exhibits and displays. It also aims at exposing younger children to activities such as identifying shapes, puppet shows and building blocks in order to stimulate their interest in science.

Forensic Science Laboratories
Activities in these state-of-the-art laboratories are specifically for school-going learners from grades 9 – 12 as well as their teachers. Learners are presented with different science-based methods of solving problems related to real life experiences. In addition, curriculum-based experiments are also performed.

Technology Research Activity Centre (TRAC)
Grades 10, 11 and 12 learners together with their educators are invited to utilise this resource, which is managed by TRAC facilitators.

Computer Laboratory
This laboratory provides Observatory visitors such as learners/students and educators with opportunities of doing their school-related work with computers. It supports them with training in the general use of computers. The laboratory also assists teachers participating in the Teachers Forum with computer literacy to enhance their classroom activities.

Resource Centre
This centre provides a platform for reading, studying, borrowing and returning of laboratory equipment and chemicals, as well as library materials to schools and/or public members. Information regarding different science careers is also accessible in the centre.

Night Tours
These tours are organised in collaboration with the Astronomy Society of South Africa (ASSA). Plans are underway to ensure that on monthly basis (and at ad hoc times depending on the event), night tours are organised in order to present the public with exciting astronomy activities. Interactive talks, discussions, demonstrations and science shows form part of the programme.


Reunert Telescope

The original Observatory in Johannesburg was initially a meteorological institution. When it was later decided to diversify into astronomical observation, the then director, Robert Innes, acquired a telescope with the help of Dr Theodore Reunert. It was the Observatory’s first piece of astronomical equipment. Then known as the nine-inch telescope, the instrument was installed in 1907, opening up a whole new view of the Universe.

One of the first observations made through the telescope was the apparent disappearance of the rings of Saturn. Fortunately, all it took was a slight retouching of the objective lens by the manufacturer, and both the telescope (and the Universe) was returned to normal. The telescope was renamed the Reunert Telescope in 1924, in honour of Dr Reunert’s instrumentation.

Innes, who was also the founding director of the Observatory, was using the telescope in conjunction with a series of photographic plates when he discovered Proxima-centauri (the star closest to our Sun) in 1915. It is a tiny Red Dwarf star some 4,22 light years away from Earth, and the third member of the Alpha Centauri triple system. This was the first of many multi-star observations that Innes subsequently documented, along with his observations of the large satellites of Jupiter.

Although the Reunert Telescope is not the most convenient instrument to use for modern-day observational astronomy, it has a lot of historical significance. To this day, more than a century later, Proxima Centauri still holds the record as being Earth’s nearest stellar neighbour.

Innes Telescope

This Telescope was named after the founding director of the Johannesburg Observatory, Sir Robert Innes. A street leading to the Observatory site and an office building Innes used were also named after him. Innes used the Reunert Telescope to discover Proxima Centauri, which still holds the record as being Earth’s nearest stellar neighbour.

The Innes Telescope is a 26,5 inch refractor telescope, which has been refurbished by SAASTA and is still functional. The ASSA uses this telescope every second Wednesday of the month to observe the skies. It is also used by SAASTA for sky viewing together with members of public and schools.


Call +27 (0)11 551-5940

Visit the Johannesburg Observatory

18A Gill Str, Observatory, Johannesburg, South Africa

View Google map to the Observatory

Directions to the Johannesburg Observatory travelling from the North:

  • Travelling along the M1 South freeway, take the Joe Slovo Offramp
  • Turn left into Houghton Ave and follow the road as it curves to the right and becomes First Ave
  • Turn right into Louis Botha Ave
  • Turn left into Acorn and left again into St. Peters
  • Turn sharp right into Bezuidenhout and left into Ecksteen
  • Turn right into Innes and follow the road until it crosses Gill
  • Turn right into Gill. The Observatory and Science Park is up ahead on your left hand side at number 18A Gill Street