I don’t know what

gets people fired up over comets (the celestial kind). Maybe the pre-scientific astrological belief that they are portents of drama and disaster – notably the appearance of Halley’s comet in the year 1066 that preceded the Norman invasion of England.

In previous centuries, there were certainly some spectacular ones, stretching right across the sky. Nowadays, perhaps because of light pollution which drowns out celestial objects in urban areas throughout the world, these are almost non-existent – in fact, the more astronomers hype the arrival of the ‘brightest’ comet this century, the more you can bet the object will turn out to resemble a minute blob of cotton wool, visible with good binoculars on one night if you are lucky.

Comet Mcnaught (comets are usually named after their discoverers) however, made a decent spectacle over Namibia last week, watched by hundreds of people crowding the hilltops around Windhoek.

Comets are actually not very interesting – they are the proverbial ‘dirty snowball’, a few kilometres across, much smaller than a self-respecting asteroid, hurtling round the sun in a highly elongated or even open-ended orbit, which means they visit us only once. The tail is a cloud of dust blown out by the rays of the sun when the comet is closest – the tail fans out ahead of the comet, and is not dragged along behind like the tail of a cat as some people assume. When I said they are not very interesting, comets are of great interest in the formation of the solar system, but that is only relevant if you have a budget of a billion dollars or so to send a probe up to one.

It’s strange that on any clear moonless night, even in Windhoek (at least before the new State House switches on its thousands of fence lights), there is much more to see – the milky way arches overhead, either Orion or the Scorpion glitters down, and you have a clear view across the galaxy. With the naked eye, you can even see our neighbour galaxy – Andromeda – two million light years away. But the hilltops of Windhoek are empty.

All this would be just passing-the-time talk, except for tragedy. Mr. Swiegers, a well-known local auto dealer, was watching the comet with some friends on the outskirts of town, when armed robbers emerged from the darkness. They were of course after the observers’ digital cameras. A shot was fired, and Mr. Swiegers was hit and killed. Despite the easily identifiable cameras, no arrests have been made.

So Namibia is the one country where amateur astronomers need to go armed. We said at the beginning that the idea of comets being a portent of disaster was just an astrological superstition, but for poor Mr. Swiegers it was the literal truth.