On Tuesday, Five-hundred-meter Aperture Spherical Telescope (FAST), nicknamed "China's Eye of Heaven", officially began its search for extraterrestrial intelligence.

As the news went viral on social networking sites, someone commented saying: "Do not answer! Do not answer! Do not Answer!"

It seems The Three-Body Problem, a science fiction by Chinese author Liu Cixin, has so deeply influenced minds that everybody is worried about the possibility of the Earth being invaded by an advanced extraterrestrial civilization.

That worry is, at least for now, unnecessary considering the universe's vastness. Of the 1,800 extraterrestrial planets discovered, less than 20 are capable of supporting life, and the nearest among them, Gliese 581, is 20.4 light-years away.

And that's life of any kind. According to Robin Hanson's great filter theory, there is less than a one in a million chance of that life evolving into higher intelligence or a civilization. And since their distance from China could even be millions or billions of light-years away, if they travel at the speed of light it would take them at least millions of years to reach us.

Therefore, do not worry about ETs invading us because that won't happen anytime soon. However, that does not mean FAST's job is meaningless. As humankind's most sensitive radio telescope, FAST can best collect signals from the universe. Researchers can distinguish even a 4 Hz difference in the signals received, meaning it can best distinguish between manmade and ET-made signals. Even the signals from a non-ET civilization are useful, because they might contain some hidden information leading to the discovery of new stars or planets.

With FAST joining the cause, humankind can browse the universe more deeply than ever before and increase knowledge about the universe. And whatever it achieves is the best evidence of China's advanced technology in astronomy and the study of the universe.

On Monday, the Pentagon released three short video clips about UFOs, shot by the US navy. More exploration will be required to rule out ETs. China's efforts in this regard will be essential.