English-section editor David Ferguson, who translated the original story from German, now suggests that last week's story of a mysterious UFO in the skies over Beijing may turn out to have the most mundane of explanations. He explains:

"I spoke to my German colleague, Till Wohler, about the UFO story on Friday, and I was fascinated when he called me late Friday afternoon to tell me that it was visible again. I watched it myself for an hour or so and photographed it from my apartment. It was very bright, high in the sky just to the south of west, and it seemed to be moving slowly on a northern trajectory.

At the time it did seem to me that it resembled the planet Venus -- Venus is the only celestial object I have ever seen shining so brightly in a western sky, with light still visible following sunset, but Till was convinced Venus ought to be much further to the south and lower in the sky.

I'm an open-minded sceptic on these matters - I don't rule out the possibility of other intelligences, and extraterrestrial or extra-dimensional travel, but I like to check such things out properly. I consulted a very useful Internet night-sky tracking website http://www.fourmilab.ch/cgi-bin/Yoursky. It took me a little while to work it out, but once I had input the right data on longitude, latitude, and time settings, I was able to identify our 'UFO', and also predict exactly where and when it would reappear on Sunday evening. It turns out to be none other than the oldest UFO chestnut of them all - the planet Venus. It's the single biggest source of mistaken UFO sightings."

Till, however, remains convinced that the object he saw and photographed the previous Monday was not Venus: "I took pictures of Venus and the moon at the end of January," he said. "My pictures on Monday were taken from the same spot. The object I photographed looked quite different. I had checked the tracking software http://www.stellarium.org to visualize the night-sky over Beijing. And I guess the ephemeris does not contain any data on UFOs..."

(China.org.cn by David Ferguson, February 23, 2009)