All those UFOs that have been spotted around China this year, closing down airports and causing general flying saucer mayhem and wonder, are on the increase. And "great events" will soon follow, an astronomer says.

"First, I'd like to say something about the conception of 'great events about UFOs,'" Wang Sichao, a planetary astronomer at Purple Mountain Observatory of the Chinese Academy of Sciences, told the Beijing Review.

"It does not mean large numbers of UFOs but refers to events of credible facts backed by observation. But these facts cannot yet be explained by existing scientific knowledge or natural phenomena," he told the English-language weekly.

Those are strong pro-UFO words from a scientist who, in September, dismissed UFO sightings over Hong Kong as "ghost images" -- reflections of outdoor lamps caught by camera lenses.

Wang has investigated UFO sightings in China for nearly 40 years and described the many types of unidentified objects that have been seen: "bolide, light spot, spiral, fan, bright star, flying rod, ball lightning and V-shaped."

The astronomer has a theory as to why, over so many decades, there hasn't been much progress in available UFO information -- presuming some UFOs are a type of extraordinary vehicle.

"The reason is that a UFO only appears randomly and often disappears rapidly in a few minutes. By the time large professional telescopes are started up, it has already disappeared. So, we can only rely on information from occasional sightings or encounters by observers," he said.

"Astronomers all over the world are now intensifying their efforts to explore extraterrestrial life. As long as we have open minds about scientific exploration of the unknown and employ multiple methods, the contact between humans and extraterrestrial life will, hopefully, come this century."

Read more at Beijing Review.