Reports of UFO sightings are expected to rise over the next few weeks as the planet Venus passes close to the Earth. Does anyone still believe in them?
We come in peace...
Astronomers expect many sky-watchers to mistake the planet Venus for some other unearthly body, as it will appear over the tops of houses and trees in the next few weeks.
Since the dawn of man, it seems we have been looking to the skies to prove that we are not alone.
Modern radar systems have become sophisticated enough to explain the vast majority of sightings as being aircraft or atmospheric conditions or planets.
And scientists remain mostly unmoved by what has been seen. They say that although some UFO sightings merit investigation, it is not because they could be alien craft.
Nonetheless, UFOs are still being seen in their hundreds across the globe.
Walter’s UFO hotline
The planet Venus will be particularly well visible in Germany over the coming weeks. A sure sign that reports of UFO sightings will increase, according to Werner Walter of Mannheim in the west of Germany.
On top of that, the comet Ikeya-Zhang can be seen streaking across skies over the Northern Hemisphere for the next several weeks.
Reports of strange objects in the sky are the reason why Walter set up the UFO hotline in 1992, the first port of call for German budding sky-gazers to talk about anything extra-terrestrial.
But the phone rang only 20 times last year. "An absolute low" says Walter. "Back in 1995, 130 people called in, but it has been downhill ever since then."
And the German control tower in Offenbach, which takes care of German airspace, now also only gets the odd call reporting unusual sightings, according to a spokesman.
In the UK, the Ministry of Defence set up a unit to look at UFO sightings in the 1950s but found no evidence of aliens, newly-released official documents have revealed.
The joint group was formed in 1951 after a spate of sightings in Sweden and the US sparked a "notable outbreak" of reports in the UK.
But the experts from the Directorate of Scientific Intelligence and the Joint Technical Intelligence Committee dismissed the prospect of alien arrivals.
They said sightings were "optical illusions and psychological delusions" - or just plain hoaxes.
But maybe the thought that we are the only form of intelligent life in the universe misses the point.
Asked if he thinks intelligent life is feasible in outer space, the British scientist Stephen Hawking replied:
"Is there intelligent life on earth then?"