The amateur astronomers who set up their telescopes next to the Johannesburg Observatory say it takes about 30 minutes of complete darkness for your eyes to gain their night vision, which makes it easier to look at stars and planets — which is why they get so frustrated by the glare of headlights from a passing car: it means a half-hour wait before you can gaze clearly at the heavens again.
Inside the observatory is the massive Innes refractor telescope, installed in 1925. At one time, the observatory played a major role in global astronomy — 579 new minor planets were spotted before 1938 — and it was there that Proxima Centauri, the closest known star to our solar system, was discovered.
The Innes telescope is particularly good for looking at stars, say the astronomers who operate the 90-year-old machinery.
On the night I am there — to celebrate the launch of a new stamp series for the Post Office — the telescope reveals a tiny but perfect image of Saturn; next, they say, it will be trained on the bright Acrux, or the bottom star, of the Southern Cross.
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