South African Astronomical Observatory

About South African Astronomical Observatory

Up on what passes for a hill, just across the Liesbeeck River from the southern suburb of Observatory, is SAAO (South African Astronomical Observatory) – the reason for the colourful suburb's name.

It lies wedged between the River Club and Valkenburg, its grounds home to a number of domes, one of which houses the Victoria telescope, built back in 1897.

Once the night skies here were as devoid of city light as Sutherland is today. It is why SALT (Southern African Large Telescope), the largest single optical telescope in the southern hemisphere, lies all the way out there, and not here.

But scientists from SALT base themselves at SAAO where there are also a series of cottages and homes on the grounds, as well as ongoing research in astronomy and astrophysics. SAAO is considered a world-class facility.

And, as an interesting aside, the Noon Day Gun that goes off in Cape Town every day gets its time signal from SAAO.

On the grounds is IAU, a large international society for outreach and development of astronomy for the world that has chosen Cape Town as its headquarters, and the McClean dome, which houses SAAO's museum and the McClean telescope.

In the library you'll find two clocks. The first shows normal South african time, the second, sidereal time – based on the Earth's rate of rotation measured relative to the fixed stars – something like the time kept by a sundial, so roughly four minutes slower than an average day.

Visit SAAO on the second and fourth Saturday of every month at 8pm, where in the auditorium you will hear a 45 minute presentation, followed by a viewing of the McClean telescope and the museum.