South Africa telescopes

The Southern African Large Telescope (SALT), which saw first light in 2005, is the largest single optical telescope in the Southern Hemisphere. Its hexagonal mirror array spans 36 feet.

SALT is part of the Southern African Astronomical Observatories (phone 023 571 2436, fax 571 1413, www.saao.ac.za), a complex of more than 10 observatories on a flat mountaintop in Sutherland, South Africa, 223 miles north of Cape Town.

Visits must be booked in advance. Up to 20 people at a time may take the guided daytime tour (R30, or near $3.80), touring several of the smaller research telescopes plus SALT and, through a large window, seeing astronomers in the control room analyzing images and data.

None of the research telescopes may be visited at night, but on night tours guests can look through two smaller telescopes nearby for R50.